private YearMonthDay getLessonStartDay() {
public YearMonthDay getLessonStartDay() {
    private YearMonthDay getLessonStartDay() {	YearMonthDay periodStart = getRoomOccupation().getPeriod().getStartYearMonthDay();	int weekOfQuinzenalStart = (getWeekOfQuinzenalStart() != null) ? getWeekOfQuinzenalStart()		.intValue() : 0;	YearMonthDay lessonStart = periodStart.plusDays(7 * weekOfQuinzenalStart);	int lessonStartDayOfWeek = lessonStart.toDateTimeAtMidnight().getDayOfWeek();	return lessonStart.plusDays(getLessonWeekDayToYearMonthDayFormat() - lessonStartDayOfWeek);    }