def all_neighbors(graph, node):
    if graph.is_directed():
        values = chain(graph.predecessors(node), graph.successors(node))
    else:
        values = graph.neighbors(node)
    return values
Detect https://bugs.launchpad.net/virtualenv/+bug/572545 .
dataset/ETHPy150Open networkx/networkx/networkx/classes/function.py/all_neighbors--crossover with--dataset/ETHPy150Open moraes/tipfy/manage/easy_install.py/_has_broken_dash_S