final Collection<AnnouncementBoard> result = new HashSet<AnnouncementBoard>(); result.addAll(getStudentCurrentExecutionCourseAnnouncementBoards()); result.addAll(getTeacherCurrentExecutionCourseAnnouncementBoards());
final Collection<AnnouncementBoard> result = new HashSet<AnnouncementBoard>(); result.addAll(getTeacherCurrentExecutionCourseAnnouncementBoards()); result.addAll(getStudentCurrentExecutionCourseAnnouncementBoards());
    public Collection<AnnouncementBoard> getCurrentExecutionCoursesAnnouncementBoards() {        final Collection<AnnouncementBoard> result = new HashSet<AnnouncementBoard>();        result.addAll(getStudentCurrentExecutionCourseAnnouncementBoards());        result.addAll(getTeacherCurrentExecutionCourseAnnouncementBoards());            return result;    }