public void readExternal(Element parentNode) throws InvalidDataException {
   super.readExternal(parentNode);
   String logMessage = JDOMExternalizerUtil.readField(parentNode, LOG_MESSAGE_OPTION_NAME);
   if (logMessage != null) {
     setLogMessage(new TextWithImportsImpl(CodeFragmentKind.EXPRESSION, logMessage));
   }
 }
 public void writeExternal(Element parentNode) throws WriteExternalException {
   super.writeExternal(parentNode);
   JDOMExternalizerUtil.writeField(
       parentNode, LOG_MESSAGE_OPTION_NAME, getLogMessage().toExternalForm());
 }