# File lib/aws/record/base.rb, line 470
      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