def __init__(self, graph, id, init={}):
        """Create a vertex object in graph.  Assumes id already in graph.
        Will add tails in init as necessary."""
        self._graph = graph  #graph to which this vertex belongs
        self._id = id
        super(VertexCommon, self).__init__()
        self.update(init)
Create a vertex object in graph.  Assumes id already in graph.
        Will add tails in init as necessary.
recipes/Python/578615_graph/recipe-578615.py