@Override
    public void infraApplicationRemoved(ApplicationId applicationId) {
        if (!supportedInfraApplications.containsKey(applicationId)) {
            throw new IllegalArgumentException("There is no infrastructure application with ID '" + applicationId + "'");
        }

        lockedRunnable(() -> {
            activeInfraInfos.remove(applicationId);
            duperModel.remove(applicationId);
        });
    }
Returns true if application is considered an infrastructure application by the DuperModel.
service-monitor/src/main/java/com/yahoo/vespa/service/duper/DuperModelManager.java