def test_append(self): A=[[1,2,3],[4,5,6]] B=[[1,2,3],[4,5,6]] expected_result=[[1, 2, 3, 1, 2, 3], [4, 5, 6, 4, 5, 6]] actual_result=Matrix.append(A, B) self.assertEqual(expected_result, actual_result)