Call `hide_all()` on all known top widgets.

def hide(self):
        """
        Call `hide_all()` on all known top widgets.
        """
        top = self.get_top_widget()
        if isinstance(top, (list, tuple)):
            for t in top:
                if t is not None:
                    t.hide_all()
        elif top is not None:
            top.hide_all()