# File lib/aws/record/abstract_base.rb, line 229
        def []= attribute_name, new_value
          self.class.attribute_for(attribute_name) do |attribute|
  
            if_tracking_changes do 
              original_value = type_cast(attribute, attribute_was(attribute.name))
              incoming_value = type_cast(attribute, new_value)
              if original_value == incoming_value
                clear_change!(attribute.name)
              else
                attribute_will_change!(attribute.name)
              end
            end
  
            @_data[attribute.name] = new_value
  
          end
        end