Function ws_handler 

pub async fn ws_handler<T>(socket: WebSocket, hub: WsHub<T>)
where
    T: Clone + Send + Serialize + DeserializeOwned + 'static,

One connected WebSocket. Spawn from your axum handler:

ws.on_upgrade(move |socket| ws_handler(socket, hub.clone()))

The future runs until the client disconnects, the keepalive ping fails, or the broadcast channel is exhausted.