add method
Adds value
to the end of this list,
extending the length by one.
The list must be growable.
final numbers = <int>[1, 2, 3];
numbers.add(4);
print(numbers); // [1, 2, 3, 4]
Implementation
@override
void add(T element) {
if (lock) return _internal.add(element);
lock = true;
_internal.add(element);
added = {super.length - 1: element};
removed = const {};
changed = const {};
notifyListeners();
}