insert method

@override void insert(int index, T element)

Insert element at the position index in this list. Listeners are notified after all objects have been repositioned.

This increases the length of the list by one and shifts all objects at or after the index towards the end of the list.

The index value must be non-negative and no greater than length.

Implementation

@override
void insert(int index, T element) {
  assert(_debugAssertNotDisposed());
  _list!.insert(index, element);
  notifyListeners();
}