If the latest request has a response, issue it as a
        reply to the RPC socket.

def poll_command_reponse(self):
        """If the latest request has a response, issue it as a
        reply to the RPC socket.
        """
        if self._command.response is not Empty:
            _logger.debug("Sending response %s", self._command.response)
            self.rpc.send(_pack(self._command.response))
            self._command = None