@Override
    public void registerListener(SuperModelListener listener) {
        synchronized (monitor) {
            listeners.add(listener);
            SuperModel superModel = superModelConfigProvider.getSuperModel();
            superModel.getAllApplicationInfos().forEach(application -> listener.applicationActivated(superModel, application));

            if (superModel.isComplete()) {
                listener.notifyOfCompleteness(superModel);
            }
        }
    }
Provides a SuperModel - a model of all application instances,  and makes it stays
up to date as applications are added, redeployed, and removed.
configserver/src/main/java/com/yahoo/vespa/config/server/SuperModelManager.java