SO 29320012 Do streams buffer

main.dart

import 'dart:async';

Stream<int> a() async* {
  for (int i = 1; i <= 10; ++i) {
    print('yield $i');
    yield i;
  }
}

main() {

//  a().listen((e) async {
//    await new Future.delayed(const Duration(seconds: 1));
//    print('a: $e');
//  });

  StreamSubscription sub;
  sub = a().listen((e) async {
    sub.pause();
    await new Future.delayed(const Duration(seconds: 1));
    print('b: $e');
    sub.resume();
  });
}