Collections.sort(possibleLessonsAndDates, NextPossibleSummaryLessonsAndDatesBean.COMPARATOR_BY_DATE);
    private void readAndSaveNextPossibleSummaryLessonsAndDates(HttpServletRequest request, ExecutionCourse executionCourse) {		List<NextPossibleSummaryLessonsAndDatesBean> possibleLessonsAndDates = new ArrayList<NextPossibleSummaryLessonsAndDatesBean>();	for (Shift shift : executionCourse.getAssociatedShiftsSet()) {	    for (Lesson lesson : shift.getAssociatedLessonsSet()) {		YearMonthDay nextPossibleSummaryDate = lesson.getNextPossibleSummaryDate();		if (nextPossibleSummaryDate != null) {		    possibleLessonsAndDates.add(new NextPossibleSummaryLessonsAndDatesBean(lesson,			    nextPossibleSummaryDate));		}	    }	}	Collections.sort(possibleLessonsAndDates, NextPossibleSummaryLessonsAndDatesBean.COMPARATOR_BY_DATE);	request.setAttribute("nextPossibleLessonsDates", possibleLessonsAndDates);    }