danwerner/multimethods — pull request #2 by exupero (2012-01-08 16:39:43+00:00)
Title: Returning existing instances when multimethods are redefined instead of raising an exception.

I was running into an issue with a module being imported multiple times and redefining the multimethod. I'm not sure this is the right solution—returning the existing instance, then re-assigning all the methods—since it creates the opportunity for hard-to-track-down bugs if one uses the same name as a multimethod that is defined in an imported module.

Now that I've talked myself out of it, thoughts?