def test_zip(self):
    c = Collection([1, 2, 3])
    self.assertEqual([(1, 4), (2, 5), (3, 6)], c.zip([4, 5, 6]).all())
def test_zip(self):
    c = Collection([1, 2, 3])
    self.assertEqual([(1, 4), (2, 5), (3, 6)], c.zip([4, 5, 6]).all())