removeObserver method
Implementation
void removeObserver(Object? observer, {String? key}) {
if (observer == null) {
log.severe('remove: the param error');
return;
}
var removedItems = [];
if (key == null) {
removedItems = _notifications.where((element) => element.observer == observer).toList();
_notifications.removeWhere((element) => element.observer == observer);
} else {
removedItems = _notifications.where((element) => element.key == key && element.observer == observer).toList();
_notifications.removeWhere((element) => element.key == key && element.observer == observer);
}
log.info('removedItems.count = ${removedItems.length}');
}