public void testEnableRootOnInstanceFail() {
    URI endpoint =
        URI.create(
            "http://172.16.0.1:8776/v1/3456/instances/44b277eb-39be-4921-be31-3d61b43651d7/root");
    InstanceApi api =
        requestsSendResponses(
                keystoneAuthWithUsernameAndPasswordAndTenantName,
                responseWithKeystoneAccess,
                authenticatedGET().method("POST").endpoint(endpoint).build(),
                HttpResponse.builder()
                    .statusCode(404)
                    .payload(payloadFromResource("/instance_root.json"))
                    .build())
            .getInstanceApi("RegionOne");

    String password = api.enableRoot("44b277eb-39be-4921-be31-3d61b43651d7");
    assertEquals(password, null);
  }