main.dart

import 'dart:async';
import 'dart:io';

void main() async {
    var controller = StreamController<int>.broadcast();


    controller.stream.listen(print);
    controller.stream.listen(print);

    controller.sink.add(1);
    controller.sink.add(1);
    controller.sink.add(1);
    controller.sink.add(1);


    streamMaker().listen(print);
}

Stream streamMaker() async* {
    yield* Directory.current.list();
    yield 123123;
    yield await Future.delayed(Duration(seconds: 1), () => 1231231231312);
}