cluster.py 文件源码

def custom_payload(self):
        """
        The custom payload returned from the server, if any. This will only be
        set by Cassandra servers implementing a custom QueryHandler, and only
        for protocol_version 4+.

        Ensure the future is complete before trying to access this property
        (call :meth:`.result()`, or after callback is invoked).
        Otherwise it may throw if the response has not been received.

        :return: :ref:`custom_payload`.
        """
        # TODO: When timers are introduced, just make this wait
        if not self._event.is_set():
            raise DriverException("custom_payload cannot be retrieved before ResponseFuture is finalized")
        return self._custom_payload