if (not route_graph_)
route_graph_ = xbt_graph_new_graph(1, nullptr);
/* Add the loopback if needed */
if (surf_network_model->loopback_ && hierarchy_ == RoutingMode::base) {
if (not route_graph_)
route_graph_ = xbt_graph_new_graph(1, nullptr);
/* Add the loopback if needed */
if (surf_network_model->loopback_ && hierarchy_ == RoutingMode::base) {