add_touch_callbacks

# File activerecord/lib/active_record/associations/builder/belongs_to.rb, line 46
      def add_touch_callbacks(reflection)
        name        = self.name
        method_name = "belongs_to_touch_after_save_or_destroy_for_#{name}"
        touch       = options[:touch]

        model.redefine_method(method_name) do
          record = send(name)

          unless record.nil?
            if touch == true
              record.touch
            else
              record.touch(touch)
            end
          end
        end

        model.after_save(method_name)
        model.after_touch(method_name)
        model.after_destroy(method_name)
      end