docs: final String debugMsg() {
      StringBuffer result;
      result = new StringBuffer(JSFormatter.format((JMFMessage)headerPart.jmfPart));
      if (payloadPart != null) {
        result.append(JSFormatter.formatWithoutPayloadData((JMFMessage)payloadPart.jmfPart));
      }
      return result.toString();
    }