anchor.diff:      }
     });
   
  -  testWithoutContext('Can upgrade and downgrade a Flutter checkout', () async {
  +  testUsingContext('Can upgrade and downgrade a Flutter checkout', () async {
       final Directory testDirectory = parentDirectory.childDirectory('flutter');
       testDirectory.createSync(recursive: true);
   
  
positive.code: import 'package:flutter_tools/src/base/terminal.dart';
  
  import '../src/common.dart';
  import 'test_utils.dart';
  
  const String _kInitialVersion = 'v1.9.1';
  
negative.code:   outputPreferences: OutputPreferences.test(wrapText: true),
  ));
  final String flutterBin = fileSystem.path.join(getFlutterRoot(), 'bin', platform.isWindows ? 'flutter.bat' : 'flutter');
  
  /// A test for flutter upgrade & downgrade that checks out a parallel flutter repo.
  void main() {
  