docs: def bitcount(self, name, start=None, end=None):
          """
          Returns the count of set bits in the value of ``key``.  Optional
          ``start`` and ``end`` paramaters indicate which bytes to consider
  
          :param name: str     the name of the redis key
          :param start: int
          :param end: int
          :return: Future()
          """
          with self.pipe as pipe:
              return pipe.bitcount(self.redis_key(name), start=start, end=end)