Iterator<WorkSchedule> workSchedulesIt = getWorkSchedulesIterator();
    public WorkSchedule workScheduleWithDate(YearMonthDay date) {        Iterator<WorkSchedule> workSchedulesIt = getWorkSchedulesIterator();        int weekNumber = getValidIntervalWeekNumberOfDate(date);        while (workSchedulesIt.hasNext()) {            WorkSchedule workSchedule = workSchedulesIt.next();            if (workSchedule.isDefinedInDate(date, weekNumber)) {                return workSchedule;            }        }        return null;    }