if (!surf_network_model->model_private->maxmin_system)
surf_network_model->model_private->maxmin_system = lmm_system_new(surf_network_model->model_private->selective_update);
if (!surf_network_model->model_private->maxmin_system)
surf_network_model->model_private->maxmin_system = lmm_system_new(surf_network_model->model_private->selective_update);