Flutter Provider: Provide 2 streams with one dependent on the other

The solution is to save the second stream (loggedInUserStream) in the state and change it whenever the first stream (authenticationStream) emits a new value (by listening to it) like in the code below:

class _FloatState extends State<Float> {  StreamSubscription<FirebaseUser> authenticationStreamSubscription;  Stream<User> loggedInUserStream;  StreamSubscription<FirebaseUser> setLoggedInUserStream() {    authenticationStreamSubscription =        FirebaseConnection.getAuthenticationStream().listen((firebaseUser) {      loggedInUserStream =          FirebaseConnection.getUserStream(uid: firebaseUser?.uid);    });  }  @override  void initState() {    super.initState();    authenticationStreamSubscription = setLoggedInUserStream();  }  @override  void dispose() {    super.dispose();    authenticationStreamSubscription.cancel();  }  @override  Widget build(BuildContext context) {    return StreamProvider<User>.value(      value: loggedInUserStream,      child: MaterialApp(        debugShowCheckedModeBanner: false,        initialRoute: LoginScreen.id,        onGenerateRoute: RouteGenerator.generateRoute,      ),    );  }}

I only needed the first stream (authenticationStream) to get the second one (loggedInUserStream) so I didn't provide it to the widgets below.