anchor.diff:      );
     }
   
  -  Uri testUri;
  +  final Future<Packages> _packagesFuture = loadPackagesFile(Uri.base.resolve('.packages'));
  +
  +  final PackageMap _flutterToolsPackageMap = PackageMap(p.join(
  +    Cache.flutterRoot,
  +    'packages',
  +    'flutter_tools',
  +    '.packages',
  +  ));
  +
  +  /// Uri of the test package.
  +  Uri get testUri => _flutterToolsPackageMap.map['test'];
   
     /// The test runner configuration.
     final Configuration _config;
   
  +  @visibleForTesting
  +  Configuration get config => _config;
  +
     /// The underlying server.
     final shelf.Server _server;
  +
  +  @visibleForTesting
  +  shelf.Server get server => _server;
   
     /// The URL for this server.
     Uri get url => _server.url;
  
positive.code: 
  import 'package:async/async.dart';
  import 'package:http_multi_server/http_multi_server.dart';
  import 'package:path/path.dart' as p; // ignore: package_path_import
  import 'package:pool/pool.dart';
  import 'package:shelf/shelf.dart' as shelf;
  
negative.code:     String shellPath,
      this.updateGoldens,
    }) {
      final shelf.Cascade cascade = shelf.Cascade()
          .add(_webSocketHandler.handler)
          .add(packagesDirHandler())
  