def post_root(item1: Item, item2: Item):
        return item1, item2  # pragma: nocover

    @router.post(
        "/router", response_model=List[Item], responses={404: {"model": List[Message]}}
    )
    def post_router(item1: Item, item2: Item):
        return item1, item2  # pragma: nocover

    app.include_router(router)
    client = TestClient(app)
    response = client.get("/openapi.json")
    data = response.json()

def test_app():
    client = TestClient(app)
    with client.websocket_connect("/") as websocket:
        data = websocket.receive_text()
        assert data == "Hello, world!"


def test_router():
    client = TestClient(app)
    with client.websocket_connect("/router") as websocket:
        data = websocket.receive_text()
        assert data == "Hello, router!"


def test_prefix_router():