pkg/front_end/testcases/nnbd_mixed/issue42387/foundation_basic_types_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.

// @dart = 2.10

typedef Future<Null> AsyncCallback();