def test_MultiGraph(self):
''' Doubled edges should become self-loops.'''
mg = nx.MultiGraph()
mg.add_edge(1, 2)
mg.add_edge(1, 2)
mg.add_edge(2, 3)
mg.add_edge(1, 3)
newG = contract(mg, (1, 2))
self.assertEqual(newG.edges(), [(1, 1), (1, 3), (1, 3)])
def test_inputUnmodified(self):
# Input graph should not be changed.
_ = contract(self.g, (1,2))
self.assertEqual(self.g.edges(), [(1, 2), (1,3), (2, 3)])
def test_simple(self):
newG = contract(self.g, (1,2))
self.assertEqual(newG.edges(), [(1,3), (1, 3)])
