CalendarWidget constructor Null safety

CalendarWidget(
  1. {Key? key,
  2. DateTime? date,
  3. DateTime? firstDate,
  4. DateTime? lastDate,
  5. List<CalendarMarker>? markers,
  6. double? width,
  7. double? height,
  8. EdgeInsets padding = Dimens.padding_zero,
  9. EdgeInsets margin = Dimens.margin_zero,
  10. bool allowControls = true,
  11. Color headerColor = Colors.teal,
  12. Color headerTextColor = Colors.white,
  13. Color contentColor = Colors.yellow,
  14. Color contentAltColor = Colors.black12,
  15. Color contentTextColor = Colors.grey,
  16. Color contentBorderColor = Colors.grey,
  17. Color markerColor = Colors.orange,
  18. Color markerTextColor = Colors.white,
  19. DataCallback? onChangeDate,
  20. DataCallback? onPressMarker,
  21. DataCallback? onLongPressMarker}
)