add method Null safety
- @override
- E element
Adds value
to the end of this list,
extending the length by one.
The list must be growable.
Implementation
@override
void add(E element) {
// Listen to the element if asked to and if it is possible
if (_propagateNotification &&
element != null &&
element is ChangeNotifier) {
element.addListener(_propagate);
}
_values.add(element);
notifyListeners();
}