final ComboBox s = new ComboBox("Restart game with select:");
s.setNullSelectionAllowed(false);
s.addItem("-- Choose value --");
s.setValue("-- Choose value --");
s.addItem(VerticalLayout.class);
s.addItem(HorizontalLayout.class);
s.addItem(GridLayout.class);
s.addListener(new ComboBox.ValueChangeListener() {
@Override
public void valueChange(ValueChangeEvent event) {