def bitcount(self, name, start=None, end=None):
with self.pipe as pipe:<EOL><INDENT>return pipe.bitcount(self.redis_key(name), start=start, end=end)<EOL><DEDENT>
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()