public void MoveAt(int oldIndex, int newIndex)
{
_verifyWrite();
T item = _list[oldIndex];
_list.RemoveAt(oldIndex);
_list.Insert(newIndex, item);
_notify(Changes.Move(oldIndex, newIndex, item));
}
public async Task MoveAt(int oldIndex, int newIndex)
{
var oldVals = _items.ToArray();
T item = _items[oldIndex];
_items.RemoveAt(oldIndex);
_items.Insert(newIndex, item);
await Changed.Invoke(Changes.Move(oldIndex, newIndex, item).Collect(oldVals, _items));
}