@Override
 public Object getPreviousValue() {
   // Calendar cal = Calendar.getInstance();
   // cal.setTime(value.getTime());
   // cal.add(calendarField, -1);
   // Date prev = cal.getTime();
   ChronoLocalDateTime<?> prev = value.minus(1, temporalUnit);
   return Objects.isNull(start) || start.compareTo(prev) <= 0 ? prev : null;
 }
 @Override
 public Object getNextValue() {
   // Calendar cal = Calendar.getInstance();
   // cal.setTime(value.getTime());
   // cal.add(calendarField, 1);
   // Date next = cal.getTime();
   ChronoLocalDateTime<?> next = value.plus(1, temporalUnit);
   return Objects.isNull(end) || end.compareTo(next) >= 0 ? next : null;
 }