    def test_frame_focus_widget_property_when_frame_focussed(self):
        """
        check the frame exposes nothing when frame is foccused
        """
        screen = MagicMock(spec=Screen, colours=8, unicode_aware=False)
        canvas = Canvas(screen, 10, 40, 0, 0)
        scene = Scene([], -1)
        form = _TestFrame(canvas)
        scene.add_effect(form)
        form.reset()

        # A Frame with a valid focus should return the widget in focus.
        layout = form._layouts[form._focus]
        layout._has_focus = True
        form._has_focus = True
        self.assertEqual(layout._columns[layout._live_col][layout._live_widget],
                         form.focussed_widget)
check the frame exposes nothing when frame is foccused
tests/test_widgets.py