@NotNull
  public static String getFileName(@Nullable String path) {
    if (path == null || path.isEmpty()) {
      return "";
    }

    int end = lastNonSeparatorIndex(path);
    int start = lastSeparatorIndex(path, end);
    if (isWindowsUNCRoot(path, start)) {
      start = -1;
    }
    return path.substring(start + 1, end + 1);
  }
@NotNull
  public static String getFileName(@Nullable String path)