[Twisted-Python] web.server.Request.process except cred.util.Unauthorized

[Kevin Turner]

A quick grep through the Twisted source doesn't show any web-related
places this is likely to get raised. It does reveal the fact that there
are two cred Unauthorized exception classes, one defined in cred.util
and the other in cred.error.  Commenting out the whole 'except
util.Unauthorized' block in server.Request.process doesn't cause any
tests to fail.

So I'd like to know:

When are we expecting util.Unauthorized to get raised?  From the
site.getResourceFor(req) call, or the resrc.render(), both, or neither? 

Can we get rid of one of the two cred Unauthorized exceptions?

Regards,

 - Kevin