As noted by Twisol, those holes previously contained `(fab a)`. I'd delete my comment now that it's addressed, but 1) it's too late, and 2) I'm too happy about

As noted by Twisol, those holes previously contained `(fab a)`. I'd delete my comment now that it's addressed, but 1) it's too late, and 2) I'm too happy about "unbound usings".