docs: public static VaadinConfirmDialog show(final UI ui,
              final String windowCaption, final String message,
              final String okCaption, final String cancelCaption, final Runnable r) {
          VaadinConfirmDialog d = getFactory().create(windowCaption, message,
                  okCaption, cancelCaption, null);
          d.show(ui, new Listener() {
              private static final long serialVersionUID = 1L;
  
              public void onClose(VaadinConfirmDialog dialog) {
                  if (dialog.isConfirmed()) {
                      r.run();
                  }
              }
          }, true);
          return d;
      }