testBasicButtonBehavior() {
    const node = dom.getElement('demoSelectionMenuButton');
    selectionMenuButton.decorate(node);
    testingEvents.fireClickSequence(node);

    assertTrue('Menu must open after click', selectionMenuButton.isOpen());

    let menuItemClicked = 0;
    let lastMenuItemClicked = null;
    events.listen(
        selectionMenuButton.getMenu(), Component.EventType.ACTION, (e) => {
          menuItemClicked++;
          lastMenuItemClicked = e.target;
        });

    const menuItem2 = dom.getElement('menuItem2');
    testingEvents.fireClickSequence(menuItem2);
    assertFalse(
        'Menu must close on clicking when open', selectionMenuButton.isOpen());
    assertEquals(
        'Number of menu items clicked should be 1', 1, menuItemClicked);
    assertEquals(
        'menuItem2 should be the last menuitem clicked', menuItem2,
        lastMenuItemClicked.getElement());
  }
Open the menu and click on the menu item inside.