action perform action event object sourc sourc sourc ui element event object old classifi object classifi object ci sourc uml combo box uml combo box box uml combo box sourc object obj box target model facad classifi state obj old classifi model facad type obj invalid element except problem classifi state just eras ci obj object cl box select item model facad classifi cl classifi cl classifi old classifi ci classifi model core helper set type ci classifi action perform 