How to delay an activity during testing


I have the following.

 s.env.OnActivity(<activity>).Return(nil).Run(func(args mock.Arguments) {
		time.Sleep(2 * time.Second)

in my workflow, after the activity is executed it calls (workflow.Now(ctx)) to store the time. I want to validate that time to validate things activities are being called in parallel vs sequential. However, when I add the sleep it seems to have no effect on the workflow clock.

I’m wondering if the delay logic is incorrect

I know there is a RegisterDelayedCallback, and looks at the example where they use this to trigger Signals but not sure how I would use this when a mocked out activity response