public List<Node> makeReadyChildren(int n, NodeResources resources) {
        return makeReadyChildren(n, 1, resources, null,
                                     index -> UUID.randomUUID().toString());
    }
Create one or more child nodes without a parent starting with index 1
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java