webman怎么在onWorkerStart中实例化数据库？

/**
 * @param $worker
 * @return mixed|void
 */
public static function start($worker){
    // 配置
    Db::setConfig(config('thinkorm'));
    // 维持mysql心跳
    if ($worker) {
        Timer::add(55, function () {
            $connections = config('thinkorm.connections', []);
            foreach ($connections as $key => $item) {
                if ($item['type'] == 'mysql') {
                    Db::connect($key)->query('select 1');
                }
            }
        });
    }
}