code: @Nullable
    public static String getFilename(@Nullable final String path) {
      if (path == null) {
        return null;
      }
  
      final int separatorIndex = path.lastIndexOf(StringUtils.FOLDER_SEPARATOR);
      return separatorIndex != -1 ? path.substring(separatorIndex + 1) : path;
    }
docs: Extract the filename from the given Java resource path, e.g.
  {@code "mypath/myfile.txt" -> "myfile.txt"}.
  
  @param path the file path (may be {@code null})
  @return the extracted filename, or {@code null} if none