docs: def zscore(self, name, value):
          """
          Return the score of an element
  
          :param name: str     the name of the redis key
          :param value: the element in the sorted set key
          :return: Future()
          """
          with self.pipe as pipe:
              return pipe.zscore(self.redis_key(name),
                                 self.valueparse.encode(value))