How to gracefully shutdown websocket with granian?

[hung-phan]

Hi there, thanks for this library. I have use it to replace uvicorn however i am not sure how to gracefully shutdown websocket server with it. When i use with fastapi asgi lifespan

    @asynccontextmanager
    async def lifespan(_: FastAPI):
        try:
            yield
        finally:
            # drain websocket
           drain_websocket()

    app_ = FastAPI(
        lifespan=lifespan
    )

Btw, i try to drain_websocket, the socket is closed by granian. I wonder what would be the best way to trigger gracefully shutdown for websocket.