CODE:

            graph.writeLock();            //Writing the new edges            for( Edge e : edges){                    graph.addEdge(e);            }                       graph.writeUnlock();

CODE:

public void execute(GraphModel graphModel, AttributeModel attributeModel) {        Graph graph = graphModel.getGraphVisible();        graph.readLock();                try {            Progress.start(progressTicket, graph.getNodeCount());            // For edges that will be removed           Vector<Edge> edges=new Vector<Edge>();            int i=0;                        for (Node m : graph.getNodes()) {                    int m_inf_n=1;                    for (Node n : graph.getNodes()) {                        if(m_inf_n==1){// in order to test only one time each couple of nodes                            if(!m.equals(n))                                m_inf_n=0;                            continue;                        }                        if(TEST){                                Edge e=graphModel.factory().new Edge(m, n);                                edges.add(e);                        }                    }                Progress.progress(progressTicket);                if (cancel) {                    break;                }            }            graph.readUnlockAll();            graph.writeLock();            //Writing the new edges            for( Edge e : edges){                    graph.addEdge(e);            }                        graph.readUnlockAll();        } catch (Exception e) {            // print stack trace as report            StringWriter sw=new StringWriter();            PrintWriter pw=new PrintWriter(sw, true);            e.printStackTrace(pw);            pw.flush();            sw.flush();            res+= sw.toString();        } finally {            //Unlock graph            graph.readUnlockAll();        }    }