-xbt_dict_t created_categories = nullptr;
-xbt_dict_t declared_marks = nullptr;
-xbt_dict_t user_host_variables = nullptr;
-xbt_dict_t user_vm_variables = nullptr;
-xbt_dict_t user_link_variables = nullptr;
-extern xbt_dict_t trivaNodeTypes;
-extern xbt_dict_t trivaEdgeTypes;
+std::set<std::string> created_categories;
+std::set<std::string> declared_marks;
+std::set<std::string> user_host_variables;
+std::set<std::string> user_vm_variables;
+std::set<std::string> user_link_variables;
+extern std::set<std::string> trivaNodeTypes;
+extern std::set<std::string> trivaEdgeTypes;