+/** @brief Set the root netzone, containing all others. Once set, it cannot be changed. */
+void Engine::set_netzone_root(s4u::NetZone* netzone)
+{
+ xbt_assert(pimpl->netzone_root_ == nullptr, "The root NetZone cannot be changed once set");
+ pimpl->netzone_root_ = static_cast<kernel::routing::NetZoneImpl*>(netzone);
+}