func testStreamRoundtrip(t *testing.T, local, remote *Manager) {
	defer testlogger.T.SetErrorTB(t)()
	defer timeout(5 * time.Second)()
	errFatal := func(err error) {
		t.Helper()
		if err != nil {
			t.Fatal(err)
		}
	}

	// We fake a local and remote server.
	remoteHost := remote.HostName()

	// 1: Echo
	register := func(manager *Manager) {
		errFatal(manager.RegisterStreamingHandler(handlerTest, StreamHandler{

Each handler, with optional subroutes can be registered with the manager using
`Manager.RegisterXHandler(handlerID, handler, subroutes...)`.

A `Handler()` function provides an HTTP handler, which should be hooked up to the appropriate route on the server.

On startup, the manager will start connecting to remotes and also starts listening for incoming connections.

	user.Manager.Name += "new2"
	if err := DB.Session(&gorm.Session{FullSaveAssociations: true}).Select("`Company`").Save(&user).Error; err != nil {
		t.Fatalf("errors happened when update: %v", err)
	}

	var user5 User
	DB.Preload("Company").Preload("Manager").Find(&user5, "id = ?", user.ID)
	if user5.Manager.Name != user4.Manager.Name {
		t.Errorf("should not update user's manager")
	} else {
		user.Manager.Name = user4.Manager.Name
	}

		CheckUser(t, user, users2[idx])
		if users2[idx].Manager == nil {
			t.Fatalf("Failed to load Manager")
		}
		// manager
		CheckUser(t, *user.Manager, *users2[idx].Manager)
		// user pet
		if users2[idx].NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")
		}
		CheckPet(t, *user.NamedPet, *users2[idx].NamedPet)
		// manager pet
		if users2[idx].Manager.NamedPet == nil {
			t.Fatalf("Failed to load NamedPet")

		*GetUser("bulk_5", Config{Account: false, Pets: 0, Toys: 3, Company: true, Manager: false, Team: 1, Languages: 3, Friends: 1}),
		*GetUser("bulk_6", Config{Account: true, Pets: 4, Toys: 3, Company: false, Manager: true, Team: 1, Languages: 3, Friends: 0}),
		*GetUser("bulk_7", Config{Account: true, Pets: 1, Toys: 3, Company: true, Manager: true, Team: 4, Languages: 3, Friends: 1}),

 *
 * {@snippet :
 * class Server {
 *   public static void main(String[] args) {
 *     Set<Service> services = ...;
 *     ServiceManager manager = new ServiceManager(services);
 *     manager.addListener(new Listener() {
 *         public void stopped() {}
 *         public void healthy() {
 *           // Services have been initialized and are healthy, start accepting requests...

 *
 * {@snippet :
 * class Server {
 *   public static void main(String[] args) {
 *     Set<Service> services = ...;
 *     ServiceManager manager = new ServiceManager(services);
 *     manager.addListener(new Listener() {
 *         public void stopped() {}
 *         public void healthy() {
 *           // Services have been initialized and are healthy, start accepting requests...

### Async Context Manager { #async-context-manager }

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

{* ../../docs_src/events/tutorial003_py39.py hl[1,13] *}

    private final ConcurrentHashMap<String, Type> usedTypes;

    private final LegacyArtifactHandlerManager manager;

    @Inject
    public DefaultTypeRegistry(Lookup lookup, LanguageRegistry languageRegistry, LegacyArtifactHandlerManager manager) {
        this.lookup = requireNonNull(lookup, "lookup cannot be null");

manager = ConnectionManager()


@app.get("/")
async def get():
    return HTMLResponse(html)


@app.websocket("/ws/{client_id}")
async def websocket_endpoint(websocket: WebSocket, client_id: int):
    await manager.connect(websocket)
    try:
        while True:
            data = await websocket.receive_text()