public String addEdge(String src_region, String src_agent, String src_plugin, String dst_region, String dst_agent, String dst_plugin, String className)
    {
        String edge_id = null;
        int count = 0;
        try
        {

            while((edge_id == null) && (count != retryCount))
            {
                edge_id = IaddEdge(src_region, src_agent, src_plugin, dst_region, dst_agent, dst_plugin, className);
                count++;
            }

            if((edge_id == null) && (count == retryCount))
            {
                System.out.println("GraphDBEngine : addEdge : Failed to add node in " + count + " retrys");
            }
        }
        catch(Exception ex)
        {
            System.out.println("GraphDBEngine : addEdge : Error " + ex.toString());
        }

        return edge_id;
    }