public function __call($name, $arguments)
    {
        if (count($arguments) != 2) {
            return '';
        }
        $this->redis->$name($arguments[0], $arguments[1]);
    }

    public function sadd($k, $v)
    {
        return $this->redis->sAdd($k, $v);
    }

    public function srem($k, $v)
    {
        return $this->redis->sRem($k, $v);
    }