How to use the pymemcache.client.PooledClient function in pymemcache

def _start(self):
        super(MemcachedDriver, self)._start()
        self.client = pymemcache_client.PooledClient(
            self.host,
            serializer=self._msgpack_serializer,
            deserializer=self._msgpack_deserializer,
            timeout=self.timeout,
            connect_timeout=self.timeout,
            max_pool_size=self.max_pool_size)
        # Run heartbeat here because pymemcache use a lazy connection
        # method and only connect once you do an operation.
        self.heartbeat()