// params = text, image, action, text, image, action, ...
//   or TextImageAction...
//   or a list of above stuff
static DynamicVStack showNiceVerticalButtons(O... params) {
  final DynamicVStack stack = makeNiceButtons_usingStack((DynamicVStack) dynamicVStack().spacing(20), params);
  JScrollPane sp = jWiderScrollPane(jfullcenter(stack));
  showCenterPackedFrame(withMargin(20, sp));
  ret stack;
}