Fixed test failures introduced in e716518a

            return obj, True

        except DatabaseError as e:

            transaction.savepoint_rollback(sid, using=self.db)

            exc_info = sys.exc_info()

            if isinstance(e, IntegrityError):

                try:

                    return self.get(**lookup), False

                except self.model.DoesNotExist:

                    pass

            six.reraise(*sys.exc_info())

            six.reraise(*exc_info)

    def _extract_model_params(self, defaults, **kwargs):

        """