anywhere, i can do something before shakehand? about pitaya HOT 5 OPEN

func main() {
	defer pitaya.Shutdown()

	s := json.NewSerializer()
	conf := configApp()

	pitaya.SetSerializer(s)
	gsi := groups.NewMemoryGroupService(config.NewConfig(conf))
	pitaya.InitGroups(gsi)
	err := pitaya.GroupCreate(context.Background(), "room")
	if err != nil {
		panic(err)
	}

	// rewrite component and handler name
	room := NewRoom()
	pitaya.Register(room,
		component.WithName("room"),
		component.WithNameFunc(strings.ToLower),
	)

	log.SetFlags(log.LstdFlags | log.Llongfile)

	http.Handle("/web/", http.StripPrefix("/web/", http.FileServer(http.Dir("web"))))

	go http.ListenAndServe(":3251", nil)

	t := acceptor.NewWSAcceptor(":3250")
	pitaya.AddAcceptor(t)
	pitaya.SetBeforeHandshake(func(s *session.Session, data *session.HandshakeData) error {

		t, ok := data.User["token"]
		if !ok {
			return fmt.Errorf("token not exist")
		}
		token, ok := t.(string)
		if !ok {
			return fmt.Errorf("token error")
		}

		logger.Log.Debugf("token ok %v", token)

		return nil
	})
	pitaya.Configure(true, "chat", pitaya.Standalone, map[string]string{}, conf)
	pitaya.Start()

type App struct {
// ...
	beforeHandshake  func(*session.Session, *session.HandshakeData) error
}

func SetBeforeHandshake(fn func(*session.Session, *session.HandshakeData) error) {
	app.beforeHandshake = fn
}