anchor.diff:  
       // For all dart files: Parse them as set their source as the parsed source
       // to "get around" any encoding issues when printing later.
  -    Map<Uri, Uint8List> copy = new Map.from(_fs.data);
  +    Map<Uri?, Uint8List?> copy = new Map.of(_fs.data);
       for (Uri? uri in _fs.data.keys) {
         if (await _shouldQuit()) break;
         String uriString = uri.toString();
  
positive.code:       // Try to load json and remove blocks.
        try {
          Map json = jsonDecode(utf8.decode(data));
          Map jsonModified = new Map.from(json);
          List packages = json["packages"];
          List packagesModified = new List.from(packages);
          jsonModified["packages"] = packagesModified;
  
negative.code: 
      if (!limitTo1) {
        if (await _shouldQuit()) return;
        Map<Uri?, Uint8List?> copy = new Map.of(_fs.data);
        // Try to remove content of i and the next 9 (10 files in total).
        for (int j = uriIndex; j < uriIndex + 10 && j < uris.length; j++) {
          Uri uri = uris[j];
  