@JsonIgnore
    public boolean isController() {
        return isHostedVespaApplicationWithId(ApplicationInstanceId.CONTROLLER) &&
                Objects.equals(clusterId, ClusterId.CONTROLLER) &&
                Objects.equals(serviceType, ServiceType.CONTROLLER);
    }
Represents a collection of service instances that together make up a service with a single cluster id.

@author bjorncs
application-model/src/main/java/com/yahoo/vespa/applicationmodel/ServiceCluster.java