title: What event can I use when setting TreeView.SelectedNode = null?
body: <p>When I set <code>SelectedNode</code> to <code>null</code> the tree updates correctly but <code>BeforeSelect</code> and <code>AfterSelect</code> do not fire.</p>
  
  <p>Is there any way to tell when the selection has been changed to null?</p>
  
  <p>My first thought is to extend the control and add an event though I would have thought something like this would already be available.</p>