// Copyright (c) 2019, 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 | |
abstract class A { | |
A foo() => null; | |
} | |
abstract class B extends A { | |
B foo(); | |
} | |
class C { | |
noSuchMethod(_) => null; | |
} | |
class D extends C implements B {} | |
main() {} |