• Object#block in <main> (pry):6
  • Student.acts_as_taggable $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:15
    • Student.acts_as_taggable_on $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:39
      • Student.taggable_on $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:70
        • Array#to_a $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:71
        • Array#flatten $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:71
        • Array#compact $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:71
        • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:71
          • Symbol#to_sym $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:71
        • Student.taggable? $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:4
        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:81
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:84
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:86
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:118
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:123
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
        • Student.tag_types= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:81
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:84
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:86
              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:118
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
              • Symbol#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:123
              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
        • Student.preserve_tag_order= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
        • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:82
          • Student.block in taggable_on $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:82
            • Student.has_many $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations.rb:1395
              • ActiveRecord::Associations::Builder::HasMany.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:21
                • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/primary_key.rb:66
                  • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:107
                    • Class#superclass $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                    • Student.method_defined_within? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                      • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                      • Module#private_method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                • ActiveRecord::Associations::Builder::HasMany.define_extensions $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:23
                  • Kernel#block_given? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:24
                • ActiveRecord::Associations::Builder::HasMany.create_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:36
                  • Kernel#kind_of? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:37
                  • Kernel#is_a? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:39
                  • ActiveRecord::Associations::Builder::HasMany.validate_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:77
                    • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:7
                      • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:9
                        • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:73
                          • Enumerable#flat_map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                            • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                              • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:136
                    • Hash#assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:75
                      • Array#flatten! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:76
                      • Hash#each_key $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                  • ActiveRecord::Associations::Builder::HasMany.build_scope $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:51
                  • ActiveRecord::Associations::Builder::HasMany.macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:3
                  • ActiveRecord::Reflection.create $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:17
                    • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:32
                      • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:409
                        • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:324
                          • Student.pluralize_table_names -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:331
                          • String#pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:31
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:32
                            • ActiveSupport::Inflector.pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:30
                              • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                  • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                    • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                              • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                  • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                  • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                  • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                    • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                  • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:412
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:413
                        • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                        • ActiveRecord::Reflection::HasManyReflection#calculate_constructable $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:596
                        • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                          • Thread::Mutex#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                        • Kernel#class $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:418
                • ActiveRecord::Associations::Builder::HasMany.define_accessors $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:101
                  • Student.generated_association_methods $GemPath0/gems/activerecord-5.1.2/lib/active_record/core.rb:235
                  • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:50
                    • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:108
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:111
                      • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:109
                        • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                    • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                      • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:55
                    • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:53
                      • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                  • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:60
                    • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:116
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:119
                      • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:117
                        • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                    • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                      • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:65
                    • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:63
                      • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:14
                  • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:84
                    • ActiveRecord::Associations::Builder::HasMany.check_dependent_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:132
                      • ActiveRecord::Associations::Builder::HasMany.valid_dependent_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:11
                      • Array#include? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:133
                    • ActiveRecord::Associations::Builder::HasMany.add_destroy_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:138
                      • Kernel#lambda $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:140
                      • Student.before_destroy -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                        • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                        • Kernel#object_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:355
                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                    • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                        • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                          • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                      • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                        • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:132
                          • Student.add_autosave_association_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:179
                            • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                            • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                            • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                            • Student.before_save -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                              • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                              • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                              • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                              • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                            • Student.after_create -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.after_update -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.define_autosave_validation_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:210
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                              • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                              • ActiveRecord::Reflection::HasManyReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:553
                                • NilClass#nil? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:554
                                • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                              • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:212
                              • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                              • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                              • Student.validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:150
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Enumerable#all? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                  • Array#each $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                    • Student.block in validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                      • Kernel#is_a? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                • Hash#each_key $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:154
                                • Hash#key? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:161
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                              • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • Student.after_validation $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:92
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                  • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.before_add_for_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.after_add_for_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.before_remove_for_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.after_remove_for_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                • ActiveRecord::Associations::Builder::HasMany.define_validations $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:124
              • ActiveRecord::Reflection.add_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:36
                • Student.clear_reflections_cache $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:124
                • Student._reflections -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                  • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                • Hash#merge $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                  • Kernel#initialize_dup $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                    • Hash#initialize_copy $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                • Student._reflections= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                  • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                    • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                    • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                      • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                        • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                          • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                            • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                    • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
            • Student.has_many $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations.rb:1395
              • ActiveRecord::Associations::Builder::HasMany.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:21
                • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/primary_key.rb:66
                  • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:107
                    • Class#superclass $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                    • Student.method_defined_within? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                      • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                      • Module#private_method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                • ActiveRecord::Associations::Builder::HasMany.define_extensions $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:23
                  • Kernel#block_given? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:24
                • ActiveRecord::Associations::Builder::HasMany.create_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:36
                  • Kernel#kind_of? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:37
                  • Kernel#is_a? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:39
                  • ActiveRecord::Associations::Builder::HasMany.validate_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:77
                    • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:7
                      • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:9
                        • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:73
                          • Enumerable#flat_map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                            • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                              • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:136
                    • Hash#assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:75
                      • Array#flatten! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:76
                      • Hash#each_key $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                        • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                          • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                  • ActiveRecord::Associations::Builder::HasMany.build_scope $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:51
                  • ActiveRecord::Associations::Builder::HasMany.macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:3
                  • ActiveRecord::Reflection.create $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:17
                    • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:32
                      • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:409
                        • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:324
                          • Student.pluralize_table_names -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:331
                          • String#pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:31
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:32
                            • ActiveSupport::Inflector.pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:30
                              • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                  • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                    • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                              • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                  • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                  • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                  • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                    • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                  • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                      • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                    • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:413
                        • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                        • ActiveRecord::Reflection::HasManyReflection#calculate_constructable $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:596
                        • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                          • Thread::Mutex#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                        • Kernel#class $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:418
                    • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:33
                      • ActiveRecord::Reflection::ThroughReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:770
                • ActiveRecord::Associations::Builder::HasMany.define_accessors $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:101
                  • Student.generated_association_methods $GemPath0/gems/activerecord-5.1.2/lib/active_record/core.rb:235
                  • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                  • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:50
                    • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:108
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:111
                      • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:109
                        • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                    • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                      • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:55
                    • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:53
                      • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                  • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:60
                    • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:116
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:119
                      • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:117
                        • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                    • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                      • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:65
                    • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:63
                      • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:14
                  • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:84
                    • ActiveRecord::Reflection::ThroughReflection#options $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                    • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                      • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                        • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:132
                          • Student.add_autosave_association_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:179
                            • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                            • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                            • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                            • ActiveRecord::Reflection::ThroughReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                              • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                            • Student.before_save -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                              • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                              • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                              • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                              • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                            • Student.after_create -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.after_update -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                              • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                  • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Student.define_autosave_validation_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:210
                              • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                              • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                              • ActiveRecord::Reflection::ThroughReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                • ActiveRecord::Reflection::HasManyReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:553
                                  • NilClass#nil? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:554
                                  • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                              • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:212
                              • ActiveRecord::Reflection::ThroughReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                              • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                              • Student.validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:150
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Enumerable#all? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                  • Array#each $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                    • Student.block in validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                      • Kernel#is_a? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                • Hash#each_key $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:154
                                • Hash#key? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:161
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                              • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • Student.after_validation $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:92
                                • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                  • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                  • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                  • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                    • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                        • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                      • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                        • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                  • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                    • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                      • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                        • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                          • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                            • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                            • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                              • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                    • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                      • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                        • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                    • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                      • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                        • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                          • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                            • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                              • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                              • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                          • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                              • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                  • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                    • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                      • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                        • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                          • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                          • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                          • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                  • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                          • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                            • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                            • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                              • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                      • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                    • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                  • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                  • ActiveRecord::Reflection::ThroughReflection#options $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                  • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.before_add_for_base_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.after_add_for_base_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.before_remove_for_base_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                    • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                      • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                        • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                          • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                            • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                              • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                    • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                      • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                      • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                              • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                              • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                        • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                          • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                        • Student.after_remove_for_base_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                          • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                            • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                  • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                  • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                    • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                • ActiveRecord::Associations::Builder::HasMany.define_validations $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:124
              • ActiveRecord::Reflection.add_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:36
                • Student.clear_reflections_cache $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:124
                • Student._reflections -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                  • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                • Hash#merge $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                  • Kernel#initialize_dup $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                    • Hash#initialize_copy $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                • Student._reflections= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                  • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                    • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                    • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                      • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                        • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                          • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                            • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                    • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
            • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:86
        • Module#include(ActsAsTaggableOn::Taggable::Core) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:94
          • Module#append_features(ActsAsTaggableOn::Taggable::Core) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:94
          • ActsAsTaggableOn::Taggable::Core.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:3
            • Kernel#extend(ActsAsTaggableOn::Taggable::Core::ClassMethods) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:4
              • Module#extend_object $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:4
              • Module#extended $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:4
            • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:6
              • Student.block in included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:6
                • Module#attr_writer $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:7
                  • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:7
                • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                  • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                    • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                      • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                    • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                      • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                    • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                    • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                    • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                      • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                        • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                          • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                            • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                          • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                            • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                      • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                        • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                        • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                      • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                          • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                            • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                              • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                      • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                        • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                          • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                            • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                        • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                          • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                            • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                  • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                      • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                    • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                            • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                              • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                  • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                    • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                      • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                        • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                              • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                              • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                              • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                              • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                      • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                              • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                  • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                    • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                  • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                    • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                            • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
            • Student.initialize_acts_as_taggable_on_core $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:15
              • Student.taggable_mixin $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:243
                • Class#new $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:244
                  • Module#initialize $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:244
              • Module#include(#<Module:0x007fc03b2647a8>) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:16
                • Module#append_features(#<Module:0x007fc03b2647a8>) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:16
                • Module#included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:16
              • Student.tag_types -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
              • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:17
                • Symbol#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:17
              • Array#each $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:17
                • Student.block in initialize_acts_as_taggable_on_core $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:17
                  • String#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:18
                  • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                    • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                      • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                        • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                        • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                      • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                        • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                          • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                        • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                  • String#to_sym $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:19
                  • String#to_sym $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:20
                  • Student.preserve_tag_order? -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                      • Kernel#public_send $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                        • Student.preserve_tag_order -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:23
                    • Student.block (2 levels) in initialize_acts_as_taggable_on_core $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:23
                      • Student.has_many $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations.rb:1395
                        • ActiveRecord::Associations::Builder::HasMany.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:21
                          • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/primary_key.rb:66
                            • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:107
                              • Class#superclass $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                              • Student.method_defined_within? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                                • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                                • Module#private_method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                          • ActiveRecord::Associations::Builder::HasMany.define_extensions $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:23
                            • Kernel#block_given? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:24
                          • ActiveRecord::Associations::Builder::HasMany.create_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:36
                            • Kernel#kind_of? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:37
                            • Kernel#is_a? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:39
                            • ActiveRecord::Associations::Builder::HasMany.validate_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:77
                              • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:7
                                • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:9
                                  • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:73
                                    • Enumerable#flat_map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                                      • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                                        • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:136
                              • Hash#assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:75
                                • Array#flatten! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:76
                                • Hash#each_key $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                            • ActiveRecord::Associations::Builder::HasMany.build_scope $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:51
                              • Proc#arity $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:54
                              • Kernel#proc $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:55
                            • ActiveRecord::Associations::Builder::HasMany.macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:3
                            • ActiveRecord::Reflection.create $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:17
                              • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:32
                                • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:409
                                  • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:324
                                    • Student.pluralize_table_names -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:331
                                    • String#pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:31
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:32
                                      • ActiveSupport::Inflector.pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:30
                                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:412
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:413
                                  • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                                  • ActiveRecord::Reflection::HasManyReflection#calculate_constructable $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:596
                                  • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                                    • Thread::Mutex#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                                  • Kernel#class $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:418
                                  • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • Module#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • String#squish $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:11
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                    • String#squish! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:19
                                      • String#gsub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:20
                                      • String#strip! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:21
                                  • ActiveSupport::Deprecation.warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:25
                                    • Kernel#caller_locations $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:26
                                    • ActiveSupport::Deprecation.warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:20
                                      • ActiveSupport::Deprecation.instance /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/singleton.rb:138
                                      • ActiveSupport::Deprecation#warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:16
                                        • ActiveSupport::Deprecation#deprecation_message $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:66
                                          • ActiveSupport::Deprecation#deprecation_caller_message $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:71
                                            • ActiveSupport::Deprecation#extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:82
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:83
                                              • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:83
                                              • Enumerable#find $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                              • Thread::Backtrace::Location#path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                              • Thread::Backtrace::Location#lineno $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                              • Thread::Backtrace::Location#label $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                            • Integer#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:102
                                              • NilClass#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:104
                                              • Integer#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:105
                                        • Kernel#tap $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:20
                                          • ActiveSupport::Deprecation#block in warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:20
                                            • ActiveSupport::Deprecation#behavior $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/behaviors.rb:60
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:21
                                              • ActiveSupport::Deprecation#block (2 levels) in warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:21
                                                • ActiveSupport::Deprecation.block in <class:Deprecation> $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/behaviors.rb:23
                                                  • ActiveSupport::Logger#warn /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:533
                                                    • ActiveSupport::Logger#add -> block (2 levels) in broadcast $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:24
                                                      • ActiveSupport::Logger#block (2 levels) in broadcast $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:24
                                                        • ActiveSupport::Logger#add $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:85
                                                          • Kernel#nil? $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:86
                                                          • ActiveSupport::Logger#level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:27
                                                            • ActiveSupport::Logger#local_level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:15
                                                              • ActiveSupport::Logger#local_log_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:11
                                                                • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                                • BasicObject#__id__ $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                                          • ActiveSupport::Logger#add /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:455
                                                            • Kernel#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:457
                                                            • NilClass#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:461
                                                            • Kernel#block_given? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:462
                                                            • ActiveSupport::Logger#format_severity /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:577
                                                            • #<Class:Time>#now /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                              • Time#initialize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                                • Integer#+ /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                            • ActiveSupport::Logger#format_message /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:581
                                                              • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:101
                                                                • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:102
                                                            • Logger::LogDevice#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:684
                                                              • Logger::LogDevice#mon_synchronize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:211
                                                                • Logger::LogDevice#mon_enter /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:185
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:186
                                                                  • Thread::Mutex#lock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:187
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:188
                                                                • Logger::LogDevice#block in write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:686
                                                                  • IO#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:695
                                                                • Logger::LogDevice#mon_exit /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:197
                                                                  • Logger::LogDevice#mon_check_owner /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:247
                                                                    • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:248
                                                                  • Thread::Mutex#unlock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:202
                                                        • ActiveSupport::Logger#add $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:85
                                                          • Kernel#nil? $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:86
                                                          • ActiveSupport::Logger#level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:27
                                                            • ActiveSupport::Logger#local_level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:15
                                                              • ActiveSupport::Logger#local_log_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:11
                                                                • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                                • BasicObject#__id__ $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                                          • ActiveSupport::Logger#add /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:455
                                                            • Kernel#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:457
                                                            • NilClass#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:461
                                                            • Kernel#block_given? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:462
                                                            • ActiveSupport::Logger#format_severity /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:577
                                                            • #<Class:Time>#now /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                              • Time#initialize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                                • Integer#+ /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                            • ActiveSupport::Logger#format_message /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:581
                                                              • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:20
                                                                • ActiveSupport::Logger::SimpleFormatter#tags_text $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:51
                                                                  • ActiveSupport::Logger::SimpleFormatter#current_tags $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:45
                                                                    • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:48
                                                                    • Thread#[] $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:48
                                                                  • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:53
                                                                • NilClass#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:21
                                                                • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:101
                                                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:102
                                                            • Logger::LogDevice#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:684
                                                              • Logger::LogDevice#mon_synchronize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:211
                                                                • Logger::LogDevice#mon_enter /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:185
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:186
                                                                  • Thread::Mutex#lock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:187
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:188
                                                                • Logger::LogDevice#block in write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:686
                                                                  • IO#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:695
                                                                • Logger::LogDevice#mon_exit /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:197
                                                                  • Logger::LogDevice#mon_check_owner /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:247
                                                                    • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:248
                                                                  • Thread::Mutex#unlock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:202
                                                  • ActiveSupport::Deprecation.debug $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:20
                                                    • ActiveSupport::Deprecation.instance /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/singleton.rb:138
                          • ActiveRecord::Associations::Builder::HasMany.define_accessors $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:101
                            • Student.generated_association_methods $GemPath0/gems/activerecord-5.1.2/lib/active_record/core.rb:235
                            • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:50
                              • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:108
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:111
                                • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:109
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                              • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                                • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                                  • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                    • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                    • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                  • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                    • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                      • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                      • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                    • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                      • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:55
                              • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:53
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                            • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:60
                              • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:116
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:119
                                • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:117
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                              • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                                • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                                  • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                    • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                    • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                  • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                    • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                      • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                      • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                    • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                      • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:65
                              • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:63
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                          • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:14
                            • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:84
                              • ActiveRecord::Associations::Builder::HasMany.check_dependent_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:132
                                • ActiveRecord::Associations::Builder::HasMany.valid_dependent_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:11
                                • Array#include? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:133
                              • ActiveRecord::Associations::Builder::HasMany.add_destroy_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:138
                                • Kernel#lambda $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:140
                                • Student.before_destroy -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                  • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                    • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                    • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                    • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                      • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                        • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                        • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                        • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                        • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                          • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                      • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                        • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                        • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                      • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                          • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                            • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                              • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                  • Kernel#object_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:355
                                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                  • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                  • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                      • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                        • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                          • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                            • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                        • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                          • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                  • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                      • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                    • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                            • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                              • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                  • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                    • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                      • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                        • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                      • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                              • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                  • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                  • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                    • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                  • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                    • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                    • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                      • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                          • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                            • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                                • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                                  • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:132
                                    • Student.add_autosave_association_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:179
                                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                                      • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                                      • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                      • Student.before_save -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                        • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                        • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                          • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                        • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                          • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                      • Student.after_create -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.after_update -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.define_autosave_validation_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:210
                                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                                        • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                                        • ActiveRecord::Reflection::HasManyReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:553
                                          • NilClass#nil? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:554
                                          • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:212
                                        • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                        • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                          • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                          • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                            • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                        • Student.validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:150
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Enumerable#all? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                            • Array#each $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                              • Student.block in validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                                • Kernel#is_a? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                          • Hash#each_key $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:154
                                          • Hash#key? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:161
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                        • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                          • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                        • Student.after_validation $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:92
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.before_add_for_tag_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.after_add_for_tag_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.before_remove_for_tag_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.after_remove_for_tag_taggings= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                          • ActiveRecord::Associations::Builder::HasMany.define_validations $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:124
                        • ActiveRecord::Reflection.add_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:36
                          • Student.clear_reflections_cache $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:124
                          • Student._reflections -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                          • Hash#merge $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                            • Kernel#initialize_dup $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                              • Hash#initialize_copy $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                          • Student._reflections= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                    • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                    • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                      • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                  • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                              • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                      • Student.has_many $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations.rb:1395
                        • ActiveRecord::Associations::Builder::HasMany.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:21
                          • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/primary_key.rb:66
                            • Student.dangerous_attribute_method? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:107
                              • Class#superclass $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                              • Student.method_defined_within? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:111
                                • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                                • Module#private_method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods.rb:112
                          • ActiveRecord::Associations::Builder::HasMany.define_extensions $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:23
                            • Kernel#block_given? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:24
                          • ActiveRecord::Associations::Builder::HasMany.create_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:36
                            • Kernel#kind_of? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:37
                            • Kernel#is_a? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:39
                            • ActiveRecord::Associations::Builder::HasMany.validate_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:77
                              • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:7
                                • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:9
                                  • ActiveRecord::Associations::Builder::HasMany.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:73
                                    • Enumerable#flat_map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                                      • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:74
                                        • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.valid_options $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:136
                              • Hash#assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:75
                                • Array#flatten! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:76
                                • Hash#each_key $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                                  • Hash#block in assert_valid_keys $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:77
                                    • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/hash/keys.rb:78
                            • ActiveRecord::Associations::Builder::HasMany.build_scope $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:51
                              • Proc#arity $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:54
                              • Kernel#proc $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:55
                            • ActiveRecord::Associations::Builder::HasMany.macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/has_many.rb:3
                            • ActiveRecord::Reflection.create $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:17
                              • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:32
                                • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:409
                                  • ActiveRecord::Reflection::HasManyReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:324
                                    • Student.pluralize_table_names -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:331
                                    • String#pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:31
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:32
                                      • ActiveSupport::Inflector.pluralize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:30
                                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                        • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                          • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                          • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                            • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                              • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                          • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                            • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                            • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                          • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                            • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                              • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                                • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                            • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                              • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:413
                                  • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                                  • ActiveRecord::Reflection::HasManyReflection#calculate_constructable $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:596
                                  • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                                    • Thread::Mutex#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:416
                                  • Kernel#class $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:418
                                  • ActiveRecord::Reflection::HasManyReflection#macro $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:686
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • Module#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:425
                                  • String#squish $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:11
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:12
                                    • String#squish! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:19
                                      • String#gsub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:20
                                      • String#strip! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/filters.rb:21
                                  • ActiveSupport::Deprecation.warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:25
                                    • Kernel#caller_locations $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:26
                                    • ActiveSupport::Deprecation.warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:20
                                      • ActiveSupport::Deprecation.instance /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/singleton.rb:138
                                      • ActiveSupport::Deprecation#warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:16
                                        • ActiveSupport::Deprecation#deprecation_message $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:66
                                          • ActiveSupport::Deprecation#deprecation_caller_message $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:71
                                            • ActiveSupport::Deprecation#extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:82
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:83
                                              • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:83
                                              • Enumerable#find $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                  • ActiveSupport::Deprecation#block in extract_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:85
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • Thread::Backtrace::Location#absolute_path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:86
                                                    • ActiveSupport::Deprecation#ignored_callstack $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:107
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                                      • String#start_with? $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:108
                                              • Thread::Backtrace::Location#path $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                              • Thread::Backtrace::Location#lineno $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                              • Thread::Backtrace::Location#label $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:89
                                            • Integer#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:102
                                              • NilClass#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:104
                                              • Integer#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/numeric/conversions.rb:105
                                        • Kernel#tap $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:20
                                          • ActiveSupport::Deprecation#block in warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:20
                                            • ActiveSupport::Deprecation#behavior $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/behaviors.rb:60
                                            • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:21
                                              • ActiveSupport::Deprecation#block (2 levels) in warn $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/reporting.rb:21
                                                • ActiveSupport::Deprecation.block in <class:Deprecation> $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/behaviors.rb:23
                                                  • ActiveSupport::Logger#warn /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:533
                                                    • ActiveSupport::Logger#add -> block (2 levels) in broadcast $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:24
                                                      • ActiveSupport::Logger#block (2 levels) in broadcast $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:24
                                                        • ActiveSupport::Logger#add $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:85
                                                          • Kernel#nil? $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:86
                                                          • ActiveSupport::Logger#level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:27
                                                            • ActiveSupport::Logger#local_level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:15
                                                              • ActiveSupport::Logger#local_log_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:11
                                                                • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                                • BasicObject#__id__ $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                                          • ActiveSupport::Logger#add /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:455
                                                            • Kernel#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:457
                                                            • NilClass#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:461
                                                            • Kernel#block_given? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:462
                                                            • ActiveSupport::Logger#format_severity /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:577
                                                            • #<Class:Time>#now /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                              • Time#initialize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                                • Integer#+ /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                            • ActiveSupport::Logger#format_message /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:581
                                                              • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:101
                                                                • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:102
                                                            • Logger::LogDevice#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:684
                                                              • Logger::LogDevice#mon_synchronize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:211
                                                                • Logger::LogDevice#mon_enter /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:185
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:186
                                                                  • Thread::Mutex#lock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:187
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:188
                                                                • Logger::LogDevice#block in write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:686
                                                                  • IO#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:695
                                                                • Logger::LogDevice#mon_exit /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:197
                                                                  • Logger::LogDevice#mon_check_owner /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:247
                                                                    • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:248
                                                                  • Thread::Mutex#unlock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:202
                                                        • ActiveSupport::Logger#add $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:85
                                                          • Kernel#nil? $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:86
                                                          • ActiveSupport::Logger#level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:27
                                                            • ActiveSupport::Logger#local_level $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:15
                                                              • ActiveSupport::Logger#local_log_id $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:11
                                                                • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                                • BasicObject#__id__ $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger_thread_safe_level.rb:12
                                                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                                                • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                                          • ActiveSupport::Logger#add /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:455
                                                            • Kernel#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:457
                                                            • NilClass#nil? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:461
                                                            • Kernel#block_given? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:462
                                                            • ActiveSupport::Logger#format_severity /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:577
                                                            • #<Class:Time>#now /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                              • Time#initialize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                                • Integer#+ /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:470
                                                            • ActiveSupport::Logger#format_message /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:581
                                                              • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:20
                                                                • ActiveSupport::Logger::SimpleFormatter#tags_text $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:51
                                                                  • ActiveSupport::Logger::SimpleFormatter#current_tags $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:45
                                                                    • #<Class:Thread>#current $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:48
                                                                    • Thread#[] $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:48
                                                                  • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:53
                                                                • NilClass#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/tagged_logging.rb:21
                                                                • ActiveSupport::Logger::SimpleFormatter#call $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:101
                                                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/logger.rb:102
                                                            • Logger::LogDevice#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:684
                                                              • Logger::LogDevice#mon_synchronize /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:211
                                                                • Logger::LogDevice#mon_enter /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:185
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:186
                                                                  • Thread::Mutex#lock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:187
                                                                  • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:188
                                                                • Logger::LogDevice#block in write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:686
                                                                  • IO#write /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/logger.rb:695
                                                                • Logger::LogDevice#mon_exit /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:197
                                                                  • Logger::LogDevice#mon_check_owner /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:247
                                                                    • #<Class:Thread>#current /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:248
                                                                  • Thread::Mutex#unlock /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/monitor.rb:202
                                                  • ActiveSupport::Deprecation.debug $GemPath0/gems/activesupport-5.1.2/lib/active_support/deprecation/instance_delegator.rb:20
                                                    • ActiveSupport::Deprecation.instance /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/singleton.rb:138
                              • Class#new $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:33
                                • ActiveRecord::Reflection::ThroughReflection#initialize $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:770
                          • ActiveRecord::Associations::Builder::HasMany.define_accessors $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:101
                            • Student.generated_association_methods $GemPath0/gems/activerecord-5.1.2/lib/active_record/core.rb:235
                            • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                            • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:50
                              • ActiveRecord::Associations::Builder::HasMany.define_readers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:108
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:111
                                • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:109
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:110
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                              • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                                • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                                  • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                    • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                    • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                  • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                    • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                      • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                      • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                    • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                      • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:55
                              • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:53
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:54
                            • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:60
                              • ActiveRecord::Associations::Builder::HasMany.define_writers $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:116
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                                • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:119
                                • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:117
                                  • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:118
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                              • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                                • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                                  • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                    • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                    • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                      • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                  • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                                    • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                      • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                        • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                                    • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                                      • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                                      • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                                        • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                                    • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                                      • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                        • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                          • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                      • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                                        • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                              • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:65
                              • Module#class_eval $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:63
                                • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:64
                          • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:14
                            • ActiveRecord::Associations::Builder::HasMany.define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:84
                              • ActiveRecord::Reflection::ThroughReflection#options $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                              • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                                • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:90
                                  • ActiveRecord::AutosaveAssociation::AssociationBuilderExtension.build $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:132
                                    • Student.add_autosave_association_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:179
                                      • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                      • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                                      • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:180
                                      • ActiveRecord::Reflection::ThroughReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                        • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                      • Student.before_save -> block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                        • Student.block in _define_before_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:125
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:126
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                        • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                          • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                        • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                          • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                      • Student.after_create -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.after_update -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                        • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                                            • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                                          • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                      • Student.define_autosave_validation_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:210
                                        • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                        • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                                        • String#intern $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:211
                                        • ActiveRecord::Reflection::ThroughReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                          • ActiveRecord::Reflection::HasManyReflection#validate? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:553
                                            • NilClass#nil? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:554
                                            • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                        • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:212
                                        • ActiveRecord::Reflection::ThroughReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                                          • ActiveRecord::Reflection::HasManyReflection#collection? $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:688
                                        • Student.define_non_cyclic_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:150
                                          • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:151
                                          • Module#define_method $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                            • Module#method_added $GemPath0/gems/activerecord-5.1.2/lib/active_record/autosave_association.rb:152
                                        • Student.validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:150
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Enumerable#all? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                            • Array#each $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                              • Student.block in validate $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                                • Kernel#is_a? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:153
                                          • Hash#each_key $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:154
                                          • Hash#key? $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations.rb:161
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:567
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                        • ActiveSupport::Callbacks::CallbackChain#block in append $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:568
                                                          • ActiveSupport::Callbacks::CallbackChain#append_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:580
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#push $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:583
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                                        • Student.after_validation $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:92
                                          • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                            • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                          • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                            • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/validations/callbacks.rb:95
                                          • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                                            • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                                              • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                                              • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                                • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                                                  • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                                                • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                                              • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                                  • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                            • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                              • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                                                • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                                                  • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                                                    • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                                      • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                        • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                                      • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                                        • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                            • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                                              • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                                                • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                                                  • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                                              • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                                                  • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                                                    • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                    • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                                      • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                                        • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                            • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                                        • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                          • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                                  • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                                                    • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                                      • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                        • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                                          • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                                            • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                                              • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                                                  • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                                                    • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                                                    • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                                    • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                                      • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                                            • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                                                    • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                                      • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                        • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                      • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                        • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                          • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                                      • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                        • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                          • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                                • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                                  • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                                              • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                                • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                                          • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                            • ActiveRecord::Reflection::ThroughReflection#name $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                            • ActiveRecord::Reflection::ThroughReflection#options $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:1021
                            • Array#each $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.before_add_for_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.after_add_for_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.before_remove_for_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                              • ActiveRecord::Associations::Builder::HasMany.block in define_callbacks $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:18
                                • ActiveRecord::Associations::Builder::HasMany.define_callback $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:31
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:32
                                  • Module#method_defined? $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:35
                                  • Student.class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:71
                                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:73
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:74
                                    • Hash#fetch $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:75
                                    • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                      • Student.block in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:77
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:79
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:82
                                        • Student.remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:10
                                          • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                          • BasicObject#instance_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                            • #<Class:Student (call 'Student.connection' to establish a connection)>.block in remove_possible_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:11
                                              • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                                • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                                • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Kernel#define_singleton_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:110
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:119
                                        • Student.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#private_method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                        • Module#attr_writer $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                          • Module#method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:124
                                  • Symbol#to_sym $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Kernel#Array $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                    • NilClass#to_a $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Array#map $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/collection_association.rb:36
                                  • Student.after_remove_for_tags= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                      • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                          • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                            • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                            • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                              • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                          • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                            • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                      • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                          • ActiveRecord::Associations::Builder::HasMany.define_validations $GemPath0/gems/activerecord-5.1.2/lib/active_record/associations/builder/association.rb:124
                        • ActiveRecord::Reflection.add_reflection $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:36
                          • Student.clear_reflections_cache $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:124
                          • Student._reflections -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                            • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Symbol#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                          • Hash#merge $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                            • Kernel#initialize_dup $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                              • Hash#initialize_copy $GemPath0/gems/activerecord-5.1.2/lib/active_record/reflection.rb:38
                          • Student._reflections= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                            • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                              • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                              • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                  • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                    • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                    • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                      • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                  • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                              • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
                  • Student.taggable_mixin $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:243
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:37
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:38
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:42
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/core.rb:46
        • Module#include(ActsAsTaggableOn::Taggable::Collection) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:95
          • Module#append_features(ActsAsTaggableOn::Taggable::Collection) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:95
          • ActsAsTaggableOn::Taggable::Collection.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:3
            • Kernel#extend(ActsAsTaggableOn::Taggable::Collection::ClassMethods) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:4
              • Module#extend_object $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:4
              • Module#extended $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:4
            • Student.initialize_acts_as_taggable_on_collection $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:9
              • Student.tag_types -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
              • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:10
                • Symbol#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:10
              • Array#each $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:10
                • Student.block in initialize_acts_as_taggable_on_collection $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:10
                  • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                    • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                      • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                        • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                        • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                      • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                        • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                          • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                        • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                  • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                    • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                      • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                        • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                        • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                      • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                        • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                          • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                        • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:11
                    • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:12
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:16
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:20
                    • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/collection.rb:24
        • Module#include(ActsAsTaggableOn::Taggable::Cache) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:96
          • Module#append_features(ActsAsTaggableOn::Taggable::Cache) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:96
          • ActsAsTaggableOn::Taggable::Cache.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:3
            • BasicObject#instance_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:6
              • Student.block in included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:6
                • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:8
                • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:16
                • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:35
                • BasicObject#singleton_method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/cache.rb:43
        • Module#include(ActsAsTaggableOn::Taggable::Ownership) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:97
          • Module#append_features(ActsAsTaggableOn::Taggable::Ownership) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:97
          • ActsAsTaggableOn::Taggable::Ownership.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:3
            • Kernel#extend(ActsAsTaggableOn::Taggable::Ownership::ClassMethods) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:4
              • Module#extend_object $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:4
              • Module#extended $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:4
            • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:6
              • Student.block in included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:6
                • Student.after_save -> block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                  • Student.block in _define_after_model_callback $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:137
                    • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                      • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                    • Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:140
                      • ActiveSupport::Callbacks::Conditionals::Value#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:150
                    • Kernel#Array $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                      • NilClass#to_a $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:143
                    • Symbol#to_s $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                    • String#intern $GemPath0/gems/activemodel-5.1.2/lib/active_model/callbacks.rb:144
                    • Student.set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:662
                      • Student.normalize_callback_params $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:610
                        • Array#first $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#include? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#shift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:611
                        • Array#extract_options! $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:22
                          • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Array#last $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:23
                          • Hash#extractable_options? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:7
                            • Kernel#instance_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:8
                          • Array#pop $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/array/extract_options.rb:24
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                            • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:614
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                      • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:665
                      • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                        • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                          • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                        • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                      • Array#map $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                        • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:673
                          • ActiveSupport::Callbacks::Callback.build $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:280
                            • Kernel#is_a? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:281
                            • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:288
                              • ActiveSupport::Callbacks::Callback#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:294
                                • ActiveSupport::Callbacks::Callback#compute_identifier $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:352
                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                  • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:354
                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:300
                                • Kernel#Array $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                                  • NilClass#to_a $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:301
                      • Student.__update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:619
                        • ActiveSupport::DescendantsTracker.descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:12
                          • ActiveSupport::DescendantsTracker.accumulate_descendants $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:39
                            • Kernel#hash $GemPath0/gems/activesupport-5.1.2/lib/active_support/descendants_tracker.rb:40
                        • Array#reverse_each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                          • Student.block in __update_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:620
                            • Student.get_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:845
                              • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                              • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:846
                            • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                              • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:622
                                • ActiveSupport::Callbacks::CallbackChain#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:552
                                  • ActiveSupport::Callbacks::CallbackChain#chain $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:576
                                  • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                    • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                      • Array#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:554
                                  • Class#new $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                                    • Thread::Mutex#initialize $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:555
                            • Student.block in set_callback $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:677
                              • ActiveSupport::Callbacks::CallbackChain#prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:571
                                • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                  • ActiveSupport::Callbacks::CallbackChain#block in prepend $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:572
                                    • ActiveSupport::Callbacks::CallbackChain#prepend_one $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:586
                                      • ActiveSupport::Callbacks::CallbackChain#remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:592
                                        • Array#delete_if $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                              • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                              • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                              • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                              • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                                • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                          • ActiveSupport::Callbacks::CallbackChain#block in remove_duplicates $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:594
                                            • ActiveSupport::Callbacks::Callback#duplicates? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:323
                                              • Module#=== $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:325
                                              • ActiveSupport::Callbacks::Callback#filter $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:304
                                              • ActiveSupport::Callbacks::Callback#matches? $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:319
                                      • Array#unshift $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:589
                              • Student.set_callbacks $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:849
                                • Student.__callbacks -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                  • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                • Symbol#to_sym $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                • Hash#merge $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                  • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                    • Hash#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/callbacks.rb:850
                                • Student.__callbacks= -> block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                  • Student.block (2 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:87
                                    • Kernel#singleton_class $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                    • Module#class_eval $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                      • #<Class:Student (call 'Student.connection' to establish a connection)>.block (3 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:88
                                        • #<Class:Student (call 'Student.connection' to establish a connection)>.remove_possible_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:3
                                          • Module#method_defined? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:4
                                          • Module#undef_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                            • BasicObject#singleton_method_undefined $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/module/remove_method.rb:5
                                        • Module#define_method $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                          • BasicObject#singleton_method_added $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                                    • Module#singleton_class? $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:93
            • Student.initialize_acts_as_taggable_on_ownership $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:19
              • Student.tag_types -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
              • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:20
                • Symbol#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:20
              • Array#each $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:20
                • Student.block in initialize_acts_as_taggable_on_ownership $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:20
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:21
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/ownership.rb:22
        • Module#include(ActsAsTaggableOn::Taggable::Related) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:98
          • Module#append_features(ActsAsTaggableOn::Taggable::Related) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:98
          • ActsAsTaggableOn::Taggable::Related.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:3
            • Kernel#extend(ActsAsTaggableOn::Taggable::Related::ClassMethods) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:4
              • Module#extend_object $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:4
              • Module#extended $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:4
            • Student.initialize_acts_as_taggable_on_related $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:9
              • Student.tag_types -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
              • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:10
                • Symbol#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:10
              • Array#each $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:10
                • Student.block in initialize_acts_as_taggable_on_related $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:10
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:11
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:12
                    • Module#alias_method $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:15
                      • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:15
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/related.rb:17
        • Module#include(ActsAsTaggableOn::Taggable::Dirty) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:99
          • Module#append_features(ActsAsTaggableOn::Taggable::Dirty) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable.rb:99
          • ActsAsTaggableOn::Taggable::Dirty.included $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:3
            • Kernel#extend(ActsAsTaggableOn::Taggable::Dirty::ClassMethods) $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:4
              • Module#extend_object $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:4
              • Module#extended $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:4
            • Student.initialize_acts_as_taggable_on_dirty $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:10
              • Student.tag_types -> block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
                • Student.block (4 levels) in class_attribute $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/class/attribute.rb:90
              • Array#map $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:11
                • Symbol#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:11
              • Array#each $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:11
                • Student.block in initialize_acts_as_taggable_on_dirty $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:11
                  • String#to_s $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:12
                  • String#singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/core_ext/string/inflections.rb:54
                    • ActiveSupport::Inflector.singularize $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:47
                      • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                        • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                        • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                          • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                      • ActiveSupport::Inflector.apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:380
                        • String#to_s $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • Kernel#dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                          • Kernel#initialize_dup $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                            • String#initialize_copy $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:381
                        • ActiveSupport::Inflector.inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:236
                          • Kernel#block_given? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:237
                          • ActiveSupport::Inflector::Inflections.instance $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:63
                            • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/map.rb:92
                              • Concurrent::Map#[] $GemPath0/gems/concurrent-ruby-1.0.5/lib/concurrent/collection/map/non_concurrent_map_backend.rb:19
                        • ActiveSupport::Inflector::Inflections::Uncountables#uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:53
                          • Array#any? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                            • ActiveSupport::Inflector::Inflections::Uncountables#block in uncountable? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                              • Regexp#match? $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/inflections.rb:54
                        • Array#each $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                          • ActiveSupport::Inflector.block in apply_inflections $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                            • String#sub! $GemPath0/gems/activesupport-5.1.2/lib/active_support/inflector/methods.rb:386
                  • Module#class_eval $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:14
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:15
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:19
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:23
                    • Module#method_added $GemPath0/gems/acts-as-taggable-on-4.0.0/lib/acts_as_taggable_on/taggable/dirty.rb:27