Methods
D
Instance Protected methods
define_method_attribute=(name)

See define_method_attribute in read.rb for an explanation of this code.

Source: show | on GitHub 

# File activerecord/lib/active_record/attribute_methods/write.rb, line 31
def define_method_attribute=(name)
  method = WriterMethodCache[name]
  generated_attribute_methods.module_eval {
    define_method "#{name}=", method
  }
end