anchor.diff:  
       // TODO(jensj): don't use full uris.
       print("""
  -# Copyright (c) 2021, the Dart project authors. Please see the AUTHORS file
  +# Copyright (c) 2022, 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.md file.
   
  
positive.code:     // Check if there now are any unused files.
      if (_latestComponent == null) return;
      Set<Uri> neededUris = _latestComponent!.uriToSource.keys.toSet();
      Map<Uri, Uint8List> copy = new Map.from(_fs.data);
      bool removedSome = false;
      if (await _shouldQuit()) return;
      for (MapEntry<Uri?, Uint8List?> entry in _fs.data.entries) {
  
negative.code:       // Try to load json and remove blocks.
        try {
          Map json = jsonDecode(utf8.decode(data));
          Map jsonModified = new Map.of(json);
          List packages = json["packages"];
          List packagesModified = new List.from(packages);
          jsonModified["packages"] = packagesModified;
  