Endpoint for retrieving the backend metadata
        :type context: satosa.context.Context
        :rtype: satosa.response.Response

        :param context: The current context
        :return: response with metadata

def _metadata_endpoint(self, context):
        """
        Endpoint for retrieving the backend metadata
        :type context: satosa.context.Context
        :rtype: satosa.response.Response

        :param context: The current context
        :return: response with metadata
        """
        satosa_logging(logger, logging.DEBUG, "Sending metadata response", context.state)

        metadata_string = create_metadata_string(None, self.sp.config, 4, None, None, None, None,
                                                 None).decode("utf-8")
        return Response(metadata_string, content="text/xml")