# File lib/paper_trail/version_concern.rb, line 100
      def timestamp_sort_order(direction = 'asc')
        [arel_table[PaperTrail.timestamp_field].send(direction.downcase)].tap do |array|
          array << arel_table[primary_key].send(direction.downcase) if self.primary_key_is_int?
        end
      end