pkg/front_end/testcases/nnbd_mixed/mixed_mode_hierarchy_generic_methods_lib.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.

class A<R> {
  Future<T> then<T>() => Future<T>.value();
}