It is, but adding the causes a bunch of errors that I didn't have time to fix. This might conflict with the convention for naming utility methods, will have to investigate further. I added this to let me document an underscored method, and $ is pretty uncommon in method names.
Hmm, looks like this commit breaks rendering for “utility” functions. If you change your Rakefile to point to the prototype.js fixture you’ll see what I mean. Know what could be causing this?