public static String getAlbumName(String name) {
    // if all characters were forbidden, the name can be empty
    if (name.equals("")) {
      return ALBUM_NAME_DEFAULT;
    }
    // . and .. are not valid names on filesystems
    if (name.equals(".") || name.equals("..")) {
      return ALBUM_NAME_DEFAULT + " " + name;
    }
    return name;
  }
We need to override the methods
extensions/data-transfer/portability-data-transfer-koofr/src/main/java/org/datatransferproject/transfer/koofr/KoofrTransmogrificationConfig.java