[Zope-ZEO] Where to put isinstance()/issubclass()?

[A.M. Kuchling]

Python's built-in isinstance() and issubclass() don't work for
ExtensionClasses.  We've written EC-aware versions of these functions
that should really be included in my ZODB distribution.  But where
should they go?  ExtensionClass is a module, not a package, so they
can't go in ExtensionClass/{tools,util}.py.  We put them in the
mems.lib.base module, which means nothing to people outside our
project.  Perhaps in ZODB.{tools,util,base}?  Any ideas?

--amk