def test_graph_edges(self):
graph = Graph([1,2,3,4], name='graph', weight=1)
self.assertRaises(KeyError, lambda: graph.add_edge(5, 4))
self.assertRaises(KeyError, lambda: graph.add_edge(4, 5))
graph.add_node(4, name='node(4)')
self.assertEquals(graph.get_node(4), {'name' : 'node(4)'})
graph.add_edge(2, 4, name='edge(2-4)')
self.assertEquals(graph.get_edge(2, 4), {'name' : 'edge(2-4)'})
