public void delete() { setExecutionCourse(null); setProfessorship(null); setShift(null); setRoom(null); setTeacher(null);
public void delete() { removeExecutionCourse(); removeProfessorship(); removeRoom(); removeShift(); removeTeacher();
    public void delete() {        setExecutionCourse(null);        setProfessorship(null);        setShift(null);        setRoom(null);        setTeacher(null);        super.deleteDomainObject();    }