workrman 怎么添加关键词自动回复呢

$worker = new Worker('websocket://0.0.0.0:8080');
$worker->onMessage = function($con, $msg){
    if ($msg === '在么') {
        $con->send('在');
    } else if ($msg === '你是机器人么') {
        $con->send('是的');
    }
};