def test_catch_extra_attribute(self):
# The mapper for PersistentMappings doesn't allow an
# extra attribute.
classification = None
ob = PersistentMapping()
ob.extra = '678'
ob['a'] = 'b'
ob['c'] = 'd'
obj_db = MockObjectDatabase()
m = self.conf.mappers["pm"]
event = SerializationEvent(
self.conf, m, '', classification, obj_db, ob)
self.assertRaises(SerializationError, m.serializer.serialize, event)
