public void assertAllocatedOn(String explanation, String hostFlavor, ApplicationId app) {
        for (Node node : nodeRepository.nodes().list().owner(app)) {
            Node parent = nodeRepository.nodes().node(node.parentHostname().get()).get();
            assertEquals(node + ": " + explanation, hostFlavor, parent.flavor().name());
        }
    }
Returns the hosts from the input list which are not retired
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java