Not sure what the point is here, but ... in my experience as the hiring manager I haven't seen huge success in testing a candidate whether they can do the exact thing they will be doing in the first 6 months (in software engineering). I had better results in asking questions that bias towards a certain set of behavior traits (yes, this has other long-term problems) and not certain skills.

I understand that some candidates don't like it, because they are obviously good at something and want to be asked questions in that field. But ... I already know you are good at it because you said it on the CV, so i'm not wasting time with that (yes, if you are a good liar it takes us longer to find out).

So your example, working as intended?