plack/Plack — pull request #479 by oalders (2014-11-26 18:07:21+00:00)
Title: Make clear return of response_cb explicit rather than implicit.

This bit me earlier this week when I wasn't paying enough attention and
included some logic in my call() method *after* calling response_cb().

There are other explicit returns in the code samples here. I think it
wouldn't hurt to make it obvious that response_cb()'s return value needs
to be returned by the Middleware.