def test_equals_2(self): self.assertEqual(next_id([5, 4, 3, 2, 1]), 0)
def test_equals(self): self.assertEqual(next_id([0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]), 11)
def test_equals_4(self): self.assertEqual(next_id([0, 0, 0, 0, 0, 0]), 1)
def test_equals_5(self): self.assertEqual(next_id([]), 0)
def test_equals_3(self): self.assertEqual(next_id([0, 1, 2, 3, 5]), 4)