def is_good_quartet_OLD(path, BMG):
    """Determine whether an induced P4 is a good quartet in the BMG."""
    if BMG.has_edge(path[0], path[2]) and BMG.has_edge(path[3], path[1]
        ) and BMG.nodes[path[0]]['color'] == BMG.nodes[path[3]]['color']:
        return True
    else:
        return False
