Null check exception when adding multiple events without startTime

[philitell]

When adding multiple events without startTime to a day - a null check exception occurs.

    for (CalendarGarbageEntry calendarGarbageEntry in selectedCalendarGarbageEntries) {
      final event = CalendarEventData<CalendarGarbageEntry>(
          date: date,
          color: Color(calendarGarbageEntry.garbageCategory.color),
          title: calendarGarbageEntry.garbageCategory.name,
          event: calendarGarbageEntry);
      newEvents.add(event);
    }

Reason for that is a bug: Sorting algorithm expects startTime even though it is optional.

// CalendarEvent:
CalendarEventData<CalendarGarbageEntry> CalendarEventData
({   
  required String title,   
  String description = "",   
  CalendarGarbageEntry? event,   
  Color color = Colors.blue,   
  DateTime? startTime,     // <----- startTime is optional/nullable
  DateTime? endTime,   
  TextStyle? titleStyle,   
  TextStyle? descriptionStyle,   
  DateTime? endDate,   
  required DateTime date, 
})



// extensions.dart
extension MyList on List<CalendarEventData> {
  // Below function will add the new event in sorted manner(startTimeWise) in
  // the existing list of CalendarEventData.
  void addEventInSortedManner(CalendarEventData event) {
    var addIndex = -1;
    for (var i = 0; i < this.length; i++) {
      if (event.startTime!.compareTo(this[i].startTime!) <= 0) {      //<---- startTime is required here
        addIndex = i;
        break;
      }
    }

    if (addIndex > -1) {
      this.insert(addIndex, event);
    } else {
      this.add(event);
    }
  }
}

Please change implementation in addEventInSortedManner or make startTime required/non-nullable