def test_in_degree_unknown_key(self):
g = Graph()
g.add_node("new")
g.add_node("node")
g.add_node("test")
g.add_edge("new", "node")
g.add_edge("node", "test", 45)
with self.assertRaises(IndexError) as context:
g.in_degree("blip")
self.assertTrue(context.exception)
def test_in_degree(self):
g = Graph()
g.add_node("new")
g.add_node("node")
g.add_node("test")
g.add_edge("new", "node")
g.add_edge("node", "test", 45)
deg = g.in_degree("node")
self.assertEqual(deg, 1)