public static Node.Builder reserve(List<String> ipAddresses, String hostname, String parentHostname, NodeResources resources, NodeType type) {
        return new Node.Builder(UUID.randomUUID().toString(), hostname, new Flavor(resources), State.reserved, type)
                .ipConfig(IP.Config.ofEmptyPool(ipAddresses))
                .parentHostname(parentHostname);
    }
Creates a node builder in the initial state (reserved)
node-repository/src/main/java/com/yahoo/vespa/hosted/provision/Node.java