def attach_importance(bg):
    """New measure working in progress.
    """
    for node in bg.nodes():
        bg.node[node]['imp'] = 0.0
    import itertools
    for u, v in itertools.combinations(bg.nodes(), 2):
        common = set(bg[u]) & set(bg[v])
        for node in common:
            bg.node[node]['imp'] += 1 / len(common)
    for node in bg.nodes():
        bg.node[node]['nimp'] = bg.node[node]['imp'] / bg.degree(node)
