xbt_node_t previous = new_xbt_graph_node(graph, src->cname(), nodes);
std::pair<surf::LinkImpl*, surf::LinkImpl*> info = privateLinks_.at(src->id());
if (info.first) { // link up
xbt_node_t previous = new_xbt_graph_node(graph, src->cname(), nodes);
std::pair<surf::LinkImpl*, surf::LinkImpl*> info = privateLinks_.at(src->id());
if (info.first) { // link up