auto* engine = simgrid::kernel::EngineImpl::get_instance();
engine->add_model(host_model);
engine->get_netzone_root()->set_host_model(host_model);
auto* engine = simgrid::kernel::EngineImpl::get_instance();
engine->add_model(host_model);
engine->get_netzone_root()->set_host_model(host_model);