getAll method
Gets all nodes data in this LinkedList and then returns them as type List. This method returns null if the list is empty.
Implementation
List<T?>? getAll() {
if (_head == null) return null;
if (_head == _tail) return [_head!.data];
List<T?> nodes = [];
_Node<T>? last = _head;
while (last != null) {
nodes.add(last.data);
last = last.next;
}
return nodes;
}