private static void renderChanges(ScrollBar scrollBar) {
   if (scrollBar != null) {
     renderProperty(scrollBar, PROP_VISIBILITY, scrollBar.getVisible(), false);
     renderListener(
         scrollBar, PROP_SELECTION_LISTENER, scrollBar.isListening(SWT.Selection), false);
   }
 }
 private static void preserveValues(ScrollBar scrollBar) {
   if (scrollBar != null) {
     preserveProperty(scrollBar, PROP_VISIBILITY, scrollBar.getVisible());
     preserveListener(scrollBar, PROP_SELECTION_LISTENER, scrollBar.isListening(SWT.Selection));
   }
 }