public static void AddIdentifiedPersonLeftHandler(DependencyObject d, RoutedIdentifiedEventHandler handler)
 {
     UIElement uie = d as UIElement;
     if (uie != null)
     {
         uie.AddHandler(IdentifiedEvents.IdentifiedPersonLeftEvent, handler);
     }
 }
 public static void RemoveIdentifiedPersonArrivedHandler(DependencyObject d, RoutedIdentifiedEventHandler handler)
 {
     UIElement uie = d as UIElement;
     if (uie != null)
     {
         uie.RemoveHandler(IdentifiedEvents.IdentifiedPersonArrivedEvent, handler);
     }
 }