instance method does_not_support_reverse?

# File activerecord/lib/active_record/relation/query_methods.rb, line 1843
      def does_not_support_reverse?(order)
        # Account for String subclasses like Arel::Nodes::SqlLiteral that
        # override methods like #count.
        order = String.new(order) unless order.instance_of?(String)

        # Uses SQL function with multiple arguments.
        (order.include?(",") && order.split(",").find { |section| section.count("(") != section.count(")") }) ||
          # Uses "nulls first" like construction.
          /\bnulls\s+(?:first|last)\b/i.match?(order)
      end