public class GetHowDoYouKnowVisualmidia extends GDQuery {
protected Object executeQuery(PrevalentSystem system) {
if(system.howDoYouKnowVisualmidia.isEmpty()) {
throw new HowDoYouKnowVisualmidiaDoesNotExistsInPersistenceException();
}
return system.howDoYouKnowVisualmidia;
}