public function move ($destination , $item) {
        if ($destination instanceof ARedisSet) {
            $destination->_count = null;
            $destination->_data = null;
            $destination = $destination->name;
        }
        $this->_count = null;
        $this->_data = null;
        return $this->getConnection ()->getClient ()->smove ($this->name , $destination , $item);
    }