shotgunsoftware/shotgunEvents — pull request #20 by Byron (2012-02-22 16:13:22+00:00)
Title: using callable(...) to determine if something is a callable 

to allow instance and classmethods, as well as static methods, or types.

Previously, isinstance(fun, FunctionType) was used, which is true only for plain functions. However, I see no reason to restrict the callable type.

For added flexibility, I would like to use classmethods as callbacks, which wouldn't work without additional effort without this patch.