- ret = xbt_graph_new_node(graph, xbt_strdup(name));
- xbt_dict_set(nodes, name, ret, nullptr);
- return ret;
+ auto elm = nodes->find(name);
+ if (elm == nodes->end()) {
+ xbt_node_t ret = xbt_graph_new_node(graph, xbt_strdup(name));
+ nodes->insert({name, ret});
+ return ret;
+ } else
+ return elm->second;