code: @Override
      public ModelNode correct(ModelNode newValue, ModelNode currentValue) {
          if(newValue.getType() == ModelType.UNDEFINED) {
              return newValue;
          }
          if(newValue.getType() != ModelType.OBJECT || currentValue.getType() != ModelType.OBJECT) {
              return newValue;
          }
          final Set<String> operationKeys = newValue.keys();
          final Set<String> currentKeys = currentValue.keys();
          for(String currentKey : currentKeys) {
              if(!operationKeys.contains(currentKey)) {
                  newValue.get(currentKey).set(currentValue.get(currentKey));
              }
          }
          return newValue;
      }
docs: /* (non-Javadoc)
  @see org.jboss.as.controller.AttributeValueCorrector#correct(org.jboss.dmr.ModelNode, org.jboss.dmr.ModelNode)