| // Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file |
| // for details. All rights reserved. Use of this source code is governed by a |
| // BSD-style license that can be found in the LICENSE file. |
| |
| // @dart = 2.9 |
| import 'dart:async'; |
| |
| class Base { |
| Future<int> method() async { |
| throw 'Should be unused'; |
| } |
| } |
| |
| class Sub1 extends Base { |
| Future<int> method() async { |
| return 1; |
| } |
| } |
| |
| class Sub2 extends Base { |
| Future<int> method() async { |
| return 2; |
| } |
| } |
| |
| help(Base object) async { |
| print(await object.method()); |
| } |
| |
| main() async { |
| await help(new Sub1()); |
| await help(new Sub2()); |
| } |