@Test
    public void provision_dual_stack_containers() {
        ProvisioningTester tester = new ProvisioningTester.Builder().zone(new Zone(Environment.prod, RegionName.from("us-east"))).flavorsConfig(flavorsConfig()).build();
        tester.makeReadyNodes(2, "host-large", NodeType.host, 10, true);
        tester.activateTenantHosts();

        ApplicationId application = ProvisioningTester.applicationId();
        List<HostSpec> hosts = tester.prepare(application, clusterSpec("myContent.t1.a1"), 2, 1, new NodeResources(1, 4, 100, 1));
        tester.activate(application, hosts);

        NodeList activeNodes = tester.nodeRepository().nodes().list().owner(application);
        assertEquals(List.of("127.0.127.2", "::2"), activeNodes.asList().get(1).ipConfig().primary());
        assertEquals(List.of("127.0.127.13", "::d"), activeNodes.asList().get(0).ipConfig().primary());
    }
Test redeployment of nodes that violates spare headroom - but without alternatives
<p>
Setup 2 hosts and allocate one app with a container on each. 2 spares
<p>
Initial allocation of app 1 --> final allocation:
<p>
|    |    |        |    |    |
|    |    |   -->  |    |    |
| 1a | 1b |        | 1a | 1b |
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/DynamicAllocationTest.java