def test_remove_node():
G = LayeredGraph()
G.add_edges_from([('a', 'b'), ('a', 'c'), ('b', 'd')])
G.ordering = Ordering([['a'], ['b', 'c'], ['d']])
assert sorted(G.nodes()) == ['a', 'b', 'c', 'd']
G.remove_node('c')
assert sorted(G.nodes()) == ['a', 'b', 'd']
assert G.ordering == Ordering([['a'], ['b'], ['d']])
def test_dummy_nodes_merge_bundles():
G = LayeredGraph()
G.add_node('a', node=ProcessGroup())
G.add_node('b', node=ProcessGroup())
G.ordering = Ordering([[['a']], [['b']]])
G = add_dummy_nodes(G, 'a', 'b', bundle_key=1)
assert G['a']['b']['bundles'] == [1]
G = add_dummy_nodes(G, 'a', 'b', bundle_key=2)
assert G['a']['b']['bundles'] == [1, 2]
assert set(G.nodes()) == {'a', 'b'}
assert set(G.edges()) == {('a', 'b')}
assert G.ordering == Ordering([[['a']], [['b']]])