@Override
        public PersistenceEngine create(DeployState deployState, StorageNode storageNode, StorageGroup parentGroup, ModelElement storageNodeElement) {
            search.addSearchNode(deployState, storageNode, parentGroup, storageNodeElement);
            return new ProtonProvider(storageNode);
        }
Initializes the engines engine on each storage node. May include creating other
nodes.
config-model/src/main/java/com/yahoo/vespa/model/content/engines/ProtonEngine.java