@Test
    public void change_to_and_from_combined_cluster_does_not_change_node_allocation() {
        var tester = new ProvisioningTester.Builder().zone(new Zone(Environment.prod, RegionName.from("us-east"))).build();
        var application = ProvisioningTester.applicationId();

        tester.makeReadyHosts(4, defaultResources).activateTenantHosts();

        // Application allocates two content nodes initially, with cluster type content
        ClusterSpec cluster = ClusterSpec.request(ClusterSpec.Type.content, ClusterSpec.Id.from("music")).vespaVersion("1.2.3").build();
        var initialNodes = tester.activate(application, tester.prepare(application, cluster,
                                                                       Capacity.from(new ClusterResources(2, 1, defaultResources))));

        // Application is redeployed with cluster type combined
        cluster = ClusterSpec.request(ClusterSpec.Type.combined, ClusterSpec.Id.from("music"))
                             .vespaVersion("1.2.3")
                             .combinedId(Optional.of(ClusterSpec.Id.from("qrs")))
                             .build();
        var newNodes = tester.activate(application, tester.prepare(application, cluster,
                                                                   Capacity.from(new ClusterResources(2, 1, defaultResources))));

        assertEquals("Node allocation remains the same", initialNodes, newNodes);
        assertEquals("Cluster type is updated",
                     Set.of(ClusterSpec.Type.combined),
                     newNodes.stream().map(n -> n.membership().get().cluster().type()).collect(Collectors.toSet()));

        // Application is redeployed with cluster type content again
        cluster = ClusterSpec.request(ClusterSpec.Type.content, ClusterSpec.Id.from("music")).vespaVersion("1.2.3").build();
        newNodes = tester.activate(application, tester.prepare(application, cluster,
                                                               Capacity.from(new ClusterResources(2, 1, defaultResources))));
        assertEquals("Node allocation remains the same", initialNodes, newNodes);
        assertEquals("Cluster type is updated",
                     Set.of(ClusterSpec.Type.content),
                     newNodes.stream().map(n -> n.membership().get().cluster().type()).collect(Collectors.toSet()));
    }
Test always uses the zone default resources
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTest.java