[Zope] Defining classes in scripts in Zope 2.7, examples are broken

What is the new convention for creating classes in scripts? Is it disallowed now? The examples (File Library, Guest Book) define exception classes in their add/upload scripts, which results in an error on Zope2.7b3 Win32. Thanks. Error Type: NameError Error Value: global name '__name__' is not defined """Create a guest book entry. """ class LimitExceeded(Exception): """raised when too many entries are submitted""" entries_folder=container.Entries # create up-to 5 unique entry ids, a real app might not impose such a # small limit, but we do because this is just an example after all n=len(entries_folder.objectIds()) if n > 4: raise LimitExceeded, "limit on number of entries (5) exceeded" id='entry_%d' % n