public void fail(String hostname) {
        int beforeFailCount = nodeRepository.nodes().node(hostname).get().status().failCount();
        Node failedNode = nodeRepository.nodes().fail(hostname, Agent.system, "Failing to unit test");
        assertTrue(nodeRepository.nodes().list(Node.State.failed).nodeType(NodeType.tenant).asList().contains(failedNode));
        assertEquals(beforeFailCount + 1, failedNode.status().failCount());
    }
Assert on the current *non retired* nodes
node-repository/src/test/java/com/yahoo/vespa/hosted/provision/provisioning/ProvisioningTester.java