def check_glue_status(self):
        if self.pk is None:
            return
        # First get this object from the database.mozdns and compare it to the
        # nameserver.nameserver.  object about to be saved.
        db_self = AddressRecord.objects.get(pk=self.pk)
        if db_self.label == self.label and db_self.domain == self.domain:
            return
        # The label of the domain changed. Make sure it's not a glue record
        Nameserver = mozdns.nameserver.models.Nameserver
        if Nameserver.objects.filter(addr_glue=self).exists():
            raise ValidationError(
                "This record is a glue record for a Nameserver. Change the "
                "Nameserver to edit this record."
            )
If this record is a "glue" record for a Nameserver instance,
dataset/ETHPy150Open mozilla/inventory/mozdns/address_record/models.py/BaseAddressRecord.check_glue_status