'Pop a request
timeout not support in this queue class'

def pop(self, timeout=0):

    pipe = self.server.pipeline()
    pipe.multi()
    pipe.zrange(self.key, 0, 0).zremrangebyrank(self.key, 0, 0)
    (results, count) = pipe.execute()
    if results:
        return self._decode_request(results[0])
