public void Insert (int index, object item)
{
if (index < 0 || index > Count)
throw new ArgumentOutOfRangeException ("Index of out range");
if (item == null)
throw new ArgumentNullException ("item");
owner.BeginUpdate ();
object_items.Insert (index, item);
owner.CollectionChanged ();
owner.EndUpdate ();
#if NET_2_0
//UIA Framework event: Item Added
OnUIACollectionChangedEvent (new CollectionChangeEventArgs (CollectionChangeAction.Add, item));
#endif
}