MenuBar
A MenuBar is a row of buttons into which various UI components can be added.
Example:
final MenuBar menuBar = new MenuBar();
menuBar.addThemeVariants(MenuBarVariant.LUMO_PRIMARY);
menuBar.addItem("Click me!", e -> new Dialog(new Label("You clicked the first item!")).open());
menuBar.addItem(new Label("Label inside"));
this.add(menuBar);