Can you add a description / example?

In D3242#65628, @emaste wrote:

Can you add a description / example?

Yup! I put up this review too soon though; there's a recently-introduced bug in here that I haven't tracked down yet. Once that's fixed I'll add more info and reviewers and so on. This is just a different implementation of https://reviews.freebsd.org/D323 based on some discussion there.