def test_many(self):
self.assertTrue(solution(0, 0, 2, 2), 0.25)
self.assertTrue(solution(1, 1, 2, 2), 0.25)
self.assertTrue(solution(1, 0, 2, 2), 0.25)
self.assertTrue(solution(1, 1, 3, 1), 1)
def test_one(self):
self.assertEqual(solution(0, 0, 1, 1), 0)
