protected function createRedisDriver()
    {
        $serverArray    = $this->config['servers'];
        $persistent     = boolval($this->config['persistent']);
        $prefix         = trim($this->config['prefix']);
        $expireTime     = intval($this->config['lifetime']);

        if ($persistent) {
            foreach ($serverArray as $k => $v) {
                $v['persistent']    = true;
                $serverArray[$k]    = $v;
            }
        }

        $redisServer    = new RedisServer($serverArray);
        $redisStore     = new RedisStore($redisServer, $prefix);
        return new CacheSessionHandler($redisStore, $expireTime);
    }