public Set getEdges()
public Set getEdges(Vertex vertex)
    public Set getEdges()    {        Iterator stateIter = this.states.values().iterator();        State    eachState = null;        Set edges = new HashSet();        while ( stateIter.hasNext() )        {            eachState = (State) stateIter.next();            edges.addAll( getEdges( eachState ) );        }        return edges;    }