def test_is_right_turn(self):
"""Test the is_right_turn method."""
points = np.array([[1, 1], [0, 0], [-1, 1], [0.8, 0.5]])
ch = ConvexHull(points)
ch.convex_hull = [1, 2]
self.assertTrue(ch.is_right_turn(0))
self.assertTrue(ch.is_right_turn(3))
ch.convex_hull = [0, 1]
self.assertTrue(ch.is_right_turn(2))
self.assertFalse(ch.is_right_turn(3))
ch.convex_hull = [1, 0]
self.assertFalse(ch.is_right_turn(2))
self.assertTrue(ch.is_right_turn(3))
