code: def report_definition_to_xml(report_definition)
        check_report_definition_hash(report_definition)
        add_report_definition_hash_order(report_definition)
        begin
          return Gyoku.xml({:report_definition => report_definition})
        rescue ArgumentError => e
          if e.message.include?("order!")
            unknown_fields =
                e.message.slice(e.message.index('['), e.message.length)
            raise AdwordsApi::Errors::InvalidReportDefinitionError,
                "Unknown report definition field(s): %s" % unknown_fields
          end
          raise e
        end
      end
docs: Renders a report definition hash into XML text.