title: How to test AjaxFormChoiceComponentUpdatingBehavior in WicketTester
body: <p>In my Wicket application I used one radio button with "yes" and "no" options.  If I select "No", I should display one dropdown choice.  I wrote code using <code>AjaxFormChoiceComponentUpdatingBehavior</code>.  How do I unittest this using WicketTester?</p>