private void assertZookeeperServerConfig(TestRoot root, int id) {
        ZookeeperServerConfig.Builder builder = new ZookeeperServerConfig.Builder();
        root.getConfig(builder, "admin/standalone/cluster-controllers/" + id);
        ZookeeperServerConfig config = new ZookeeperServerConfig(builder);
        assertEquals(3, config.server().size());
        assertEquals(id, config.myid());
        Collection<Integer> serverIds = Collections2.transform(config.server(), ZookeeperServerConfig.Server::id);
        assertTrue(serverIds.contains(id));
    }
Test for creating cluster controllers under the admin tag.
config-model/src/test/java/com/yahoo/vespa/model/admin/ClusterControllerTestCase.java