    def test_shoot_screen(self):
        """
        Test that ShootScreen works as expected.
        """
        screen = MagicMock(spec=Screen, colours=8)
        canvas = Canvas(screen, 10, 40, 0, 0)
        canvas.centre("Hello World!", 5)
        effect = ShootScreen(canvas, canvas.width // 2, canvas.height // 2, 100, diameter=10)
        self.check_effect(canvas,
                          effect,
                          lambda value: self.assertIn(chr(value[0]),
                                                      'HeloWrd! '),
                          is_blank=False,
                          iterations=4)
Test that ShootScreen works as expected.
tests/test_particles.py