webman 调用函数，被调用函数怎么不返回，直接返回给用户呢

function a(int $num){
    try{
        $res = test($num);
        $res = test($num+1);
        $res = test($num+2);
        return \response($res);
    }catch(\Throwable $e){
        return \response($e->getMessage());
    }
}

function test($num){
    if($num%2){
        throw new Exception('message',1112233);
    }
    return $num;
}