public WorkflowActionResponse deactivate(String workflowId, User caller) {
    Checks.notNull(caller, "caller cannot be null to deactivate workflow [%s]", workflowId);
    String timeline = workflowDao.deactivate(workflowId, caller);
    LOG.info(timeline);
    TimelineEvent event =
        TimelineActionEvent.builder()
            .action(Actions.WorkflowAction.DEACTIVATE)
            .author(caller)
            .message(timeline)
            .build();
    return WorkflowActionResponse.from(workflowId, event);
  }
@Test
  public void testDeactivate() {
    when(workflowDao.deactivate("sample-minimal-wf", tester)).thenReturn("foo");
    actionHandler.deactivate("sample-minimal-wf", tester);
    verify(workflowDao, times(1)).deactivate("sample-minimal-wf", tester);
  }