> I have thought about merging delegator and colorizer into one module, possibly with percolator included, and adding a module docstring that explains how they work together.  This would still be only a few hundred lines.  (And multiple htests in one file are not an issue.)  What do you think?

undo also uses delegator.Delegator as a base class.  It might be odd for it to come from colorizer.delegator.  I like the idea of explaining how they all work together though.

> I have not seriously looked at that idea yet.
Neither have I.  There are other things I'd like to get done (in this and other modules) before thinking about that one though.

> In the first code comment I mentioned a follow-up code change.

OK, I'll create an issue for that.  I *really* want to rename the `any` function too.  It took a lot of willpower to not touch it when writing the tests.  :-)

> Did you have anything in mind to work on or did you pick this for the fun and challenge?

:-)  Since the goal is to add tests for everything, I figured I'd tackle this one.  But, I specifically thought it would be good to have tests in place in order to work on #29287.