code: public void add(ValidationResultsModel validationResultsModel) {
  		if (children.add(validationResultsModel)) {
  			validationResultsModel.addValidationListener(this);
  			validationResultsModel.addPropertyChangeListener(HAS_ERRORS_PROPERTY, this);
  			validationResultsModel.addPropertyChangeListener(HAS_WARNINGS_PROPERTY, this);
  			validationResultsModel.addPropertyChangeListener(HAS_INFO_PROPERTY, this);
  			if ((validationResultsModel.getMessageCount() > 0))
  				fireChangedEvents();
  		}
  	}
docs: Add a validationResultsModel as a child to this one. Attach listeners and
  if it already has messages, fire events.
  
  @param validationResultsModel