HashSet nodes = (HashSet)assigned.clone();
HashSet nodes = (HashSet)layout.assigned.clone();
    private static double placementCost()     {	HashSet nodes = (HashSet)assigned.clone();	RawBackend.addAll(nodes, FileVisitor.fileReaders);		Iterator nodesIt = nodes.iterator();	HashSet routers = new HashSet();	double sum = 0.0;	while(nodesIt.hasNext()) {	    FlatNode node = (FlatNode)nodesIt.next();	    sum += placementCostHelper(node, routers);	}	return sum;    }