'Async version of flush_all().
Returns:
A UserRPC instance whose get_result() method returns True on
success, False on RPC or server error.'

def flush_all_async(self, rpc=None):

    request = MemcacheFlushRequest()
    self._add_app_id(request)
    response = MemcacheFlushResponse()
    return self._make_async_call(rpc, 'FlushAll', request, response, self.__flush_all_hook, None)
