touch_later

# File activerecord/lib/active_record/touch_later.rb, line 12
    def touch_later(*names) # :nodoc:
      unless persisted?
        raise ActiveRecordError,           cannot touch on a new or destroyed record object. Consider using          persisted?, new_record?, or destroyed? before touching.squish
      end

      @_defer_touch_attrs ||= timestamp_attributes_for_update_in_model
      @_defer_touch_attrs |= names
      @_touch_time = current_time_from_proper_timezone

      surreptitiously_touch @_defer_touch_attrs
      add_to_transaction
      @_new_record_before_last_commit ||= false

      # touch the parents as we are not calling the after_save callbacks
      self.class.reflect_on_all_associations(:belongs_to).each do |r|
        if touch = r.options[:touch]
          ActiveRecord::Associations::Builder::BelongsTo.touch_record(self, changes_to_save, r.foreign_key, r.name, touch, :touch_later)
        end
      end
    end