def test_all_variants7(self):
listed = [[1, 2], [3], [4]]
expected = [[1, 3, 4], [2, 3, 4]]
self.assertEqual(expected, all_variants(listed))
def test_all_variants8(self):
listed = [[1, 2], [3, 4], [5]]
expected = [[1, 3, 5], [1, 4, 5], [2, 3, 5], [2, 4, 5]]
self.assertEqual(expected, all_variants(listed))
def test_all_variants4(self):
listed = [[1, 2]]
expected = [[1], [2]]
self.assertEqual(expected, all_variants(listed))