pkg/front_end/testcases/general/issue41210b/issue41210.dart

// Copyright (c) 2020, 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.

import 'issue41210_lib.dart';

class C with A, B {} // error

class E with A, D {} // ok

main() {
  print(C().method(0));
}