def METHOD_NAME(self):
    """
    Test that SerpentFirework works as expected.
    """
    screen = MagicMock(spec=Screen, colours=8)
    canvas = Canvas(screen, 10, 40, 0, 0)
    effect = SerpentFirework(canvas, 4, 4, 25)
    self.check_effect(canvas,
                      effect,
                      lambda value: self.assertIn(chr(value[0]), '|+- '),
                      iterations=20)