Accessing GWT element of UI components

Is there any way to access the GWT element that implements a given Vaadin widget? For instance, when I study the code, I see that MenuBar creates a element at its root and defines items underneath.

To fend off expected replies, I get that this isn’t recommended, and that Vaadin isn’t tied to GWT, or even to the web as its GUI front-end. If I can get access to the GWT element for a given widget, even if I have to cast it, I can use GWT’s ARIA support library to add roles and improve the accessibility of my app. Once I’ve verified that these changes work as expected, I can then migrate them into core and contribute patches. But for the moment, it’d be far easier to add ARIA support if I can just get at the GWT element from my app.