/// <summary>
 /// Constructs a new selector property binding for the given Selector element.
 /// </summary>
 /// <param name="selector">The selector element to be bound to the data property.</param>
 protected SelectorPropertyBinding(Selector selector)
     : base(selector)
 {
     selector.SelectionChanged += OnSelectionChanged;
     selector.AddHandler(TextBox.TextChangedEvent, new TextChangedEventHandler(OnTextChanged));
 }