Vaadin attach class to Page?

How can I mock 'Page' and set the class's page to my mock? (Is that even possible?)

public class Example extends CssLayout(){

    public void notification(){
        Notification notif = new Notification("Title", "Message", Notification.Type.HUMANIZED_MESSAGE);
        notif.setStyleName("Warning");
        notif.setPosition(Position.TOP_CENTER);
        notif.setDelayMsec(10000);
        notif.show(Page.getCurrent());

    }
}

What I want to do :

Example example = new Example();
Page p = mock(Page.class);
example.setPage(p)

Thanks for any help!