using hobbit to monitor the number of files

Say, in a mail or print spool. I know hobbit can check the age or existence of a file, but how about the number of files in a dir?

I'm sure it's trivial to do, but I haven't run across this yet, so before I reinvent the wheel, I thought I'd ask.

I would like hobbit to report on the number of files in a given location, and then generate an alert if it's above the warning or fatal levels.

Thanks.