@Override
    public StatusHandler.ContainerStatusPageServer get(String cluster) {
        return status.get(cluster);
    }
Since we hack around injecting a running ZK here by providing one through the configurer instead,
we must also let the last configurer shut down this controller, to ensure this is shut down
before the ZK server it had injected from the configurers.
clustercontroller-apps/src/main/java/com/yahoo/vespa/clustercontroller/apps/clustercontroller/ClusterController.java