How i can open vaadin menu bar

I have standart vaadin example:


    MenuBar settings = new MenuBar();
    MenuItem settingsMenu = settings.addItem("",
            null);
    settingsMenu.setIcon(new ThemeResource("loupe.ico"));
    settingsMenu.setStyleName("icon-cog");
    settingsMenu.addItem("Settings", cmd);
    settingsMenu.addItem("Preferences", cmd);
    settingsMenu.addSeparator();
    settingsMenu.addItem("My Account", cmd);

How i can programmatically open menu or select one of his points.