// Copyright 2016 The Chromium Authors. All rights reserved.// Use of this source code is governed by a BSD-style license that can be// found in the LICENSE file.import'package:flutter/widgets.dart';import'package:flutter_test/flutter_test.dart';Future<Null>guardedHelper(WidgetTestertester){returnTestAsyncUtils.guard(()async{awaittester.pumpWidget(newText('Hello'));});}voidmain(){testWidgets('TestAsyncUtils - custom guarded sections',(WidgetTestertester)async{debugPrint=(Stringmessage,{intwrapWidth}){print(message);};awaittester.pumpWidget(newContainer());expect(find.byElementType(Container),isNotNull);guardedHelper(tester);expect(find.byElementType(Container),isNull);// this should fail});}