if (person.hasTeacher()) {
if (person != null && person.hasTeacher()) {
    public boolean isMember(Person person) {	if (person.hasTeacher()) {	    for (final Professorship professorship : person.getTeacher().getProfessorships(		    ExecutionYear.readCurrentExecutionYear())) {		if (professorship.isResponsibleFor()) {		    return true;		}	    }	}	return false;    }