void main() async {
  final t1 = () => Future.delayed(Duration(seconds: 1), () => print('1'));
  final t2 = () => Future.delayed(Duration(seconds: 3), () => print('3'));
  final t3 = () => Future.delayed(Duration(seconds: 2), () => print('2'));

  final timers = [t1, t2, t3];

  print('Running');

  Stopwatch stopwatch = new Stopwatch()..start();
  // for (final timer in timers) {
  //   await timer();
  // }
  await Future.wait(timers.map((timer) => timer()));
  print('executed in ${stopwatch.elapsed}');
}