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