t_no_context_takeover:             pmce_string += "; client_no_context_takeover"         if self.request_no_context_takeover:             pmce_string += "; server_no_context_takeover"         return pmce_string      def __json__(self):         """         Returns a JSON serializable object representation.          :returns: JSON serializable representation.         :rtype: dict         """         return {'extension': self.EXTENSION_NAME,                 '