def test_collision(self):
h1 = Hover(0, 0, North)
h2 = Hover(0, 1, North)
obstacles = [h1, h2]
h1.set_obstacles(obstacles)
h2.set_obstacles(obstacles)
self.assertRaises(CollisionDetected, h1.move)
h2.turn_left()
h2.turn_left()
self.assertRaises(CollisionDetected, h2.move)
