testKeyPressWithNoHighlightedItem() {
    popup.decorate(menu);
    popup.attach(anchor);
    events.fireKeySequence(anchor, KeyCodes.SPACE);
    assertTrue(popup.isVisible());
    try {
      events.fireKeySequence(menu, KeyCodes.SPACE);
    } catch (e) {
      fail(
          'Crash attempting to reference null selected menu item after ' +
          'keyboard event.');
    }
  }
Tests that there is no crash when hitting a key when no menu item is
highlighted.