update method
Implementation
void update(CalendarState? state) {
// TODO(google): Disable CSS transitions here somehow
this.calendarState = state;
if (weeks != null) {
weeks!.forEach((w) => w.update(state));
}
if (state == null || state.resolution != CalendarResolution.months) {
_classes = [];
} else {
_classes = state.selections
.where((selection) =>
containsDate(selection.start!) || containsDate(selection.end!))
.expand((selection) => ['boundary', 'boundary-${selection.id}'])
.toList();
}
}