Object#block in __pry__ (pry):47
- Student#name_changed? $GemPath0/gems/activemodel-5.1.2/lib/active_model/attribute_methods.rb:383
  - Student#attribute_changed? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/dirty.rb:224
    - Student#emit_warning_if_needed $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/dirty.rb:248
    - Student#attribute_changed? $GemPath0/gems/activemodel-5.1.2/lib/active_model/dirty.rb:180
      - Student#changes_include? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/dirty.rb:267
        Student#changes_include? $GemPath0/gems/activemodel-5.1.2/lib/active_model/dirty.rb:204
        Student#changed_attributes $GemPath0/gems/activemodel-5.1.2/lib/active_model/dirty.rb:175
        ActiveSupport::HashWithIndifferentAccess#key? $GemPath0/gems/activesupport-5.1.2/lib/active_support/hash_with_indifferent_access.rb:153
        ActiveSupport::HashWithIndifferentAccess#convert_key $GemPath0/gems/activesupport-5.1.2/lib/active_support/hash_with_indifferent_access.rb:288
        Kernel#kind_of? $GemPath0/gems/activesupport-5.1.2/lib/active_support/hash_with_indifferent_access.rb:289
        Hash#key? $GemPath0/gems/activesupport-5.1.2/lib/active_support/hash_with_indifferent_access.rb:154
        Student#mutation_tracker $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_methods/dirty.rb:241
        ActiveRecord::AttributeMutationTracker#changed? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_mutation_tracker.rb:38
        String#to_s $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_mutation_tracker.rb:39
        Set#include? /home/z/.rbenv/versions/2.4.0/lib/ruby/2.4.0/set.rb:232
        ActiveRecord::AttributeSet#[] $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_set.rb:12
        ActiveRecord::LazyAttributeHash#[] $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute_set/builder.rb:41
        ActiveRecord::Attribute::FromUser#changed? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:54
        ActiveRecord::Attribute::FromUser#changed_from_assignment? $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:153
        ActiveRecord::Attribute::FromUser#original_value $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:42
        ActiveRecord::Attribute::FromDatabase#original_value $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:42
        ActiveRecord::Attribute::FromDatabase#type_cast $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:162
        ActiveModel::Type::String#deserialize $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/value.rb:21
        ActiveModel::Type::String#cast $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/value.rb:35
        Kernel#nil? $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/value.rb:36
        ActiveModel::Type::String#cast_value $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/string.rb:14
        Module#=== $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/string.rb:16
        Class#new $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/string.rb:16
        String#initialize $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/string.rb:16
        ActiveRecord::Attribute::FromUser#value $GemPath0/gems/activerecord-5.1.2/lib/active_record/attribute.rb:36
        ActiveModel::Type::String#changed? $GemPath0/gems/activemodel-5.1.2/lib/active_model/type/value.rb:62