Subclass? Plugin? Mixin? Monkey Patch?

Howdy,

I've just sent a patch to Andy Armstrong for TAP::Harness that will  
allow me to mix different kinds of tests in a single harness (Perl,  
Ruby, SQL, whatever), just as long as they all emit TAP, of course.  
I'd like to take advantage of this in my Build scripts. It looks like  
the simplest thing to do would be to subclass Module::Build and  
override `do_tests()` to do what I want (and maybe  
`find_test_files()`, as well, since I'd likely use a different  
filename suffix for different kinds of tests).

So what's the best way for me to do this? Eric has chastised me  
publicly for Module::Build::JSAN, so I guess that subclassing isn't  
necessarily the best way to go. I may want to use this in more than  
one module, though, so I do need some way to make it available. So  
what's the suggested course? Do we have some sort of plugin system,  
yet? Or should I just monkey-patch Module::Build to make it do what I  
want (sorry, I programmed Ruby for a year and a half).

Thanks for your advice!

Best,

David