private static ClusterStateDeriver createIdentityClonedBucketSpaceStateDeriver() {
        return (state, space) -> state.clone();
    }
A "consolidated" cluster state is guaranteed to have up-to-date information on which nodes are
up or down even when the whole cluster is down. The regular, published cluster state is not
normally updated to reflect node events when the cluster is down.
clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetController.java