anchor.diff:    String target,
     String flxPath,
     String aotPath,
  -  List<String> addFiles,
     ApkKeystoreInfo keystore
   }) async {
     // Validate that we can find an android sdk.
  
positive.code:     argParser.addOption('aot-path',
        help: 'Path to the ahead-of-time compiled snapshot directory.\n'
              'If this is not provided, an AOT snapshot will be built.');
      argParser.addOption('add-file',
        help: 'Add a file to the APK (must have the format <path/in/APK>=<local/file/path>).',
        allowMultiple: true);
      argParser.addOption('keystore',
        help: 'Path to the keystore used to sign the app.');
      argParser.addOption('keystore-password',
  
negative.code:   }
  
    Map<String, File> extraFiles = <String, File>{};
    if (FileSystemEntity.isDirectorySync(_kDefaultAssetsPath)) {
      Directory assetsDir = new Directory(_kDefaultAssetsPath);
      for (FileSystemEntity entity in assetsDir.listSync(recursive: true)) {
  