[ZODB-Dev] is there a way to add one's own resource manager in ZODB 3?

[Ury Marshak]

Is it possible to write a cusom transactional resource manager 
to participate in ZODB transactions? I've looked into 
http://www.zope.org/Documentation/Developer/Models/ZODB and
was left with the impression that there was no provision
for that

Thanks,
Ury