StatePair pair = new StatePair(fromVertex,toVertex);
DeterministicEdge edge = existingEdges.get(pair);
if (edge == null)
{
edge = new DeterministicDirectedSparseGraph.DeterministicEdge(fromVertex,toVertex);
edge.addUserDatum(JUConstants.LABEL, new HashSet<String>(), UserData.CLONE);
g.addEdge(edge);existingEdges.put(pair,edge);
}
Set<String> labels = (Set<String>)edge.getUserDatum(JUConstants.LABEL);
labels.add(label);