public function setHost($host = null)
    {
        if ($host === null) {
            $host = '127.0.0.1';
        }

        if (substr($host, 0, 6) == 'ssl://') {
            $this->_protocol = 'ssl';
            $this->_secure = 'ssl';
            $host = substr($host, 6);
        }
        $this->_host = $host;
    }