if (hasTeacher()) { final Collection<AnnouncementBoard> result = new HashSet<AnnouncementBoard>(); for (final Professorship professorship : getTeacher().getProfessorships()) { final AnnouncementBoard board = professorship.getExecutionCourse().getBoard(); if (board != null && (board.hasReader(this) || board.hasWriter(this))) { result.add(board); } } return result;
if (!hasTeacher()) { return Collections.emptyList();
    private Collection<AnnouncementBoard> getTeacherCurrentExecutionCourseAnnouncementBoards() {	if (hasTeacher()) {	    final Collection<AnnouncementBoard> result = new HashSet<AnnouncementBoard>();            for (final Professorship professorship : getTeacher().getProfessorships()) {                final AnnouncementBoard board = professorship.getExecutionCourse().getBoard();                if (board != null && (board.hasReader(this) || board.hasWriter(this))) {                    result.add(board);                }            }            return result;        }	return Collections.EMPTY_SET;    }