future3.dart

void future_constructor_delayed() {
  Future.delayed(
    Duration(seconds: 3),
    () => 'Future.delayed(3 secs) done')
    .then((value) { print('$value'); })
    .whenComplete(
      () { print('Future.delayed(3 secs) completed'); });

  Future.delayed(
    Duration(seconds: 10),
    () => 'Future.delayed(10 secs) done')
    .timeout(Duration(seconds: 5))
    .whenComplete(
      () { print('Future.delayed(10 secs) completed'); })
    .then((value) { print('$value'); })
    .catchError((error) { print('error $error'); });
}

// output:
// Future.delayed(3 secs) done
// Future.delayed(3 secs) completed
// Future.delayed(10 secs) completed
// error TimeoutException after 0:00:05.000000: Future not completed