When I should use Stream<WebSocket> or just WebSocket

[Tom William]

I see in this link

https://api.dart.dev/stable/2.7.1/dart-io/WebSocketTransformer-class.html

so when I should use this code:

HttpServer server;
server.listen((request) {
  if (...) {
    WebSocketTransformer.upgrade(request).then((websocket) {
      ...
    });
  } else {
    // Do normal HTTP request processing.
  }
});

and When I should use this code:


server.transform(new WebSocketTransformer()).listen((webSocket) => ...);


Assume I want to stream vedio from server side to client side?!