def test_directed_edge_set(self):
""" Set an attribute of a directed edge """
v0 = DirectedVertex(val='v0')
v1 = DirectedVertex(val='v1')
e01 = DirectedEdge((v0, v1))
e01.set('weight', 5)
self.assertEqual(e01.attrs, {'weight': 5})
e01.set(0, 1)
self.assertEqual(e01.attrs, {'weight': 5, 0: 1})
