JavaFX 2.0 :: How To Subclass TableViewBehavior

There are a few things lacking in the TableView's keyboard navigation handlers. In tracing the code, the behavior is handled via TableViewBehavior and its super classes. If I want to augment that behavior, how do I do it?
 
Ideally, I would like to subclass TableViewBehavior, but I don't see how I can do it. This gets created in the TableViewSkin ctor:
 
   public TableViewSkin(final TableView<T> tableView) {
        super(tableView, new TableViewBehavior<T>(tableView));
...
   }
 
but as you can see there is no factory method to create the behavior class. If there was, I could subclass TableViewSkin and override the factory method.