def by_object_last_week(self, obj):
        """Return LogEntries of the related object for the last week."""
        last_week_date = datetime.datetime.today() - datetime.timedelta(days=7)
        ctype = ContentType.objects.get_for_model(obj)
        return self.filter(content_type__pk=ctype.pk, object_id=obj.pk,
            action_time__gt=last_week_date)