@property<EOL><INDENT>def marking_thru(self):<DEDENT>
self_django_type = ContentType.objects.get_for_model(self)<EOL>return Marking2X.objects.filter(content_type__pk=self_django_type.id,<EOL>object_id=self.id)<EOL>
Return the back-pointer to  markings that
may have been attached via Django's content type mechanism.