public static FleetControllerId fromOptions(FleetControllerOptions options) {
        return new FleetControllerId(options.clusterName(), options.fleetControllerIndex());
    }
Uniquely identifies a running FleetController: cluster name + index.

@author hakon
clustercontroller-core/src/main/java/com/yahoo/vespa/clustercontroller/core/FleetControllerId.java