def proto_error(self, requestID, fail):
        """
        (internal) Deal with an error.

        @param requestID: The request ID.
        @param fail: The failure.
        """
        d = self.waitingForAnswers[requestID]
        del self.waitingForAnswers[requestID]
        d.errback(self.unserialize(fail))

        (internal) Deal with an error.

        @param requestID: The request ID.
        @param fail: The failure.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/spread/pb.py