Use this if you are writing your own expectation. See
vignette("custom-expectation") for details
expect(ok, failure_message, info = NULL, srcref = NULL)
Was the expectation successful?
What message should be shown if the expectation was not successful?
Additional information. Included for backward compatibility only and new expectations should not use it.
Only needed in very rare circumstances where you need to forward a srcref captured elsewhere.