public static ClusterId getContentClusterName(ApplicationInstance application, HostName hostName) {
        Set<ClusterId> contentClusterIdsOnHost = application.serviceClusters().stream()
                .filter(VespaModelUtil::isContent)
                .filter(cluster -> clusterHasInstanceOnHost(cluster, hostName))
                .map(ServiceCluster::clusterId)
                .collect(Collectors.toSet());

        if (contentClusterIdsOnHost.size() != 1) {
            throw new IllegalArgumentException("Expected exactly one content cluster within application " +
                    application.applicationInstanceId() + " and host " + hostName + ", but found " +
                    contentClusterIdsOnHost.size() + ": " + contentClusterIdsOnHost + ", application: " +
                    application);
        }

        return contentClusterIdsOnHost.iterator().next();
    }
@Test
    public void testGetContentClusterName() {
        ClusterId contentClusterName = VespaModelUtil.getContentClusterName(application, distributor0.hostName());
        assertEquals(CONTENT_CLUSTER_ID, contentClusterName);
    }