public void setClusterControllers(ClusterControllerContainerCluster clusterControllers, DeployState deployState) {
        this.clusterControllers = clusterControllers;
        if (isHostedVespa) {
            // Prefer to put Slobroks on the admin cluster running cluster controllers to avoid unnecessary
            // movement of the slobroks when there are changes to the content cluster nodes
            removeSlobroks();
            addSlobroks(createSlobroksOn(clusterControllers, deployState));
        }
    }
Returns the log server for this, or null if none
config-model/src/main/java/com/yahoo/vespa/model/admin/Admin.java