docs: def jing(rng_filepath, *xml_filepaths):
      """Run jing.jar using the RNG file against the given XML file."""
      cmd = ['java', '-jar']
      cmd.extend([str(JING_JAR), str(rng_filepath)])
      for xml_filepath in xml_filepaths:
          cmd.append(str(xml_filepath))
      proc = subprocess.Popen(cmd,
                              stdin=subprocess.PIPE,
                              stdout=subprocess.PIPE,
                              stderr=subprocess.PIPE,
                              close_fds=True)
      out, err = proc.communicate()
      return _parse_jing_output(out.decode('utf-8'))