public static function remove($key)
    {
        $old = null;

        if (!static::has($key)) {
            return $old;
        }

        if (!static::$is_decrypt[$key]) {
            $old = Crypto::decrypt($_COOKIE[$key]);

            unset(static::$is_decrypt[$key]);
        }

        static::add($key, null, -1000);
        unset($_COOKIE[$key]);

        return $old;
    }