docs: public static VaadinConfirmDialog show(final UI ui,
              final String windowCaption, final String message,
              final String okCaption, final String cancelCaption,
              final String notOKCaption, final Listener listener) {
          VaadinConfirmDialog d = getFactory().create(windowCaption, message,
                  okCaption, cancelCaption, notOKCaption);
          d.show(ui, listener, true);
          return d;
      }