public static void RemovePreviewContactDownHandler(DependencyObject element, ContactEventHandler handler)
 {
     EventUtility.RemoveEventHandler(element, PreviewContactDownEvent, handler);
 }
 public static void RemoveContactDoubleClickHandler(DependencyObject element, ContactEventHandler handler)
 {
     EventUtility.RemoveEventHandler(element, ContactDoubleClickEvent, handler);
 }