Function unsubscribeFromTopic

unsubscribeFromTopic(subscriber, websocketAlias?): void
Unsubscribe for WebSocket messages.
Parameters
- subscriber: string | UpWebSocketSubscriber
  
  WebSocket subscriber object or subscriber key.
- Optional websocketAlias: string
  
  WebSocket alias, otherwise the default alias is used.
Returns void
Example
UpWebSocketSubscriber
```
ix.websocket.unsubscribeFromTopic(mySubscriber);
```
String
```
ix.websocket.unsubscribeFromTopic("<SUBSCRIBER-KEY>");
```