    def test_cpu_saving(self):
        """
        Check Frame rate limiting is even more extreme when in cpu saving mode.
        """
        screen = MagicMock(spec=Screen, colours=8, unicode_aware=False)
        canvas = Canvas(screen, 10, 40, 0, 0)
        scene = Scene([], -1)
        form = _TestFrame(canvas, reduce_cpu=True)
        scene.add_effect(form)
        form.reset()

        # In this mode, it shouldn't matter where we are on the Frame - all
        # widgets will basically say they don't need animation.
        self.assertEqual(form.reduce_cpu, True)
        self.assertEqual(form.frame_update_count, 1000000)

        # Shift focus away from a text input, just to be sure.
        self.process_keys(form, [Screen.KEY_BACK_TAB])
        self.assertEqual(form.frame_update_count, 1000000)
Check Frame rate limiting is even more extreme when in cpu saving mode.
tests/test_widgets.py