@Test
public void whenUpdatingNextActivationTimeUpdateWorkflowInstanceWorks() {

  UpdateWorkflowInstanceRequest req = new UpdateWorkflowInstanceRequest();
  req.nextActivationTime = new DateTime(2014, 11, 12, 17, 55, 0);
  resource.updateWorkflowInstance(3, req);
  verify(workflowInstances).updateWorkflowInstance(
      (WorkflowInstance) argThat(allOf(hasField("state", equalTo(null)), hasField("status", equalTo(null)))),
      (WorkflowInstanceAction) argThat(allOf(hasField("stateText", equalTo("API changed nextActivationTime to "
          + req.nextActivationTime + ".")), hasField("type", equalTo(externalChange)))));
}