@Override
 public List<ModelNode> getAllowedValues() {
   final List<ModelNode> result = new ArrayList<ModelNode>();
   for (JournalType type : JournalType.values()) {
     result.add(new ModelNode().set(type.name()));
   }
   return result;
 }
 @Override
 public void validateParameter(String parameterName, ModelNode value)
     throws OperationFailedException {
   super.validateParameter(parameterName, value);
   if (value.getType() != ModelType.EXPRESSION) {
     String str = value.asString();
     try {
       JournalType.valueOf(str);
     } catch (IllegalArgumentException e) {
       List<JournalType> list = Arrays.asList(JournalType.values());
       throw new OperationFailedException(
           new ModelNode().set(MESSAGES.invalidParameterValue(str, parameterName, list)));
     }
   }
 }