code: public static String appendTrailingDelimiter(String _filePath) {
          if (_filePath == null) {
              return null;
          }
          if (!_filePath.endsWith(File.separator)) {
              _filePath += File.separator;
          }
          return _filePath;
      }
docs: Appends the OS specific path delimiter to the end of the String, if it is missing.
  @param _filePath file path
  @return String