main.dart

import 'dart:async';

Future main() async {
  print('start');
  
  final futures = <Future>[
    fetchLong(),
    fetchShort(),
  ];

  await Future.wait(futures);
  
  print('all done');
}

Future<void> fetchShort() {
  return Future.delayed(Duration(seconds: 4), () => print('Short!'));
}

Future<void> fetchLong() {
  return Future.delayed(Duration(seconds: 5), () => print('Long!'));
}