button with dropdown menu (second try)

    $tb = $page->add('View_ButtonMenuButton')->set('Test');
    $menu = $tb->addButtonMenu()->setType('vertical');
    $menu->addMenuItem('open','Open...')
        ->addMenuItem('save','Save')
        ->sub()
            ->addMenuItem('saveas','Save as...')
        ->end()
        ->addMenuItem('delete','Delete')
    ;