def test_difference(self): self.assertEqual(graph.difference([1, 2], [2, 3]), [1])
def test_difference(self): self.assertEqual(graph.difference([1,2],[2,3]), [1])
def test_difference(self): self.assertEqual(graph.difference([1, 2], [2, 3]), [1])
def test_difference(self): self.assertEqual(graph.difference([1,2],[2,3]), [1])