addEventToLocation method
Add an event to the specified location in the locationDateIdMap.
Implementation
void addEventToLocation(Location? location, CalendarEvent event) {
final locationString = location?.name ?? defaultLocation;
final dates = event.internalRange(location: location).dates();
for (final date in dates) {
locationDateIdMap[locationString]!.update(
toKey(date),
(value) => value..add(event.id),
ifAbsent: () => {event.id},
);
}
}