[Zope-dev] add new base classes dynamically with hotfixes

Hi! I want to modify existing Zope classes without touching the code of the product packages. This how-to seems to fit exactly my needs: http://www.zope.org/Members/Caseman/Dynamic_Hotfix But one thing I don't know how to do:

1. Add new base classes to existing classes, such as CatalogAware (use the __bases__ attribute).

It works with (classic) Classes, as described here: http://www.linuxjournal.com/article.php?sid=4540 But Zope uses also ExtensionClasses. The __bases__ attribute of ExtensionClasses appears to be read-only and ExtensionClass is a run-out model (see http://mail.python.org/pipermail/python-dev/2001-December/018807.html ). So what I'm looking for, is a work-around. Any ideas? Thanks! Yuppie