protected function getUuid()
    {
        $content = $this->vbot->http->get('https://login.weixin.qq.com/jslogin', ['query' => [
            'appid' => 'wx782c26e4c19acffb',
            'fun'   => 'new',
            'lang'  => 'zh_CN',
            '_'     => time(),
        ]]);

        preg_match('/window.QRLogin.code = (\d+); window.QRLogin.uuid = \"(\S+?)\"/', $content, $matches);

        if (!$matches) {
            throw new FetchUuidException('fetch uuid failed.');
        }

        $this->vbot->config['server.uuid'] = $matches[2];
    }