code: def request_payload(resource, headers)
        if headers
          format_specified = headers['Content-Type']
          if format_specified.nil?
            resource.to_xml
          elsif format_specified.downcase.include?('xml')
            resource.to_xml
          elsif format_specified.downcase.include?('json')
            resource.to_json
          else
            resource.to_xml
          end
        else
          resource.to_xml
        end
      end
docs: Extract the request payload in the specified format, defaults to XML