private static ServiceClusterKey toServiceClusterKey(ServiceInfo serviceInfo) {
        ClusterId clusterId = getClusterId(serviceInfo);
        ServiceType serviceType = toServiceType(serviceInfo);
        return new ServiceClusterKey(clusterId, serviceType);
    }
Reverse of toApplicationInstanceId, put in this file because it its inverse is.
service-monitor/src/main/java/com/yahoo/vespa/service/model/ApplicationInstanceGenerator.java