code: public static String getFileName(String fullPath) {
          Preconditions.checkNotNull(fullPath, "path can not be null");
          int winDelimiterPos = fullPath.lastIndexOf(WINDOWS_DELIMITER);
          int linDelimiterPos = fullPath.lastIndexOf(LINUX_DELIMITER);
          int pos = Math.max(winDelimiterPos, linDelimiterPos);
          return fullPath.substring(pos + 1, fullPath.length());
      }
docs: Returns file name by given absolute or relative file location.
  TODO: remove unused?