def validate_no_cname(self):
        return
        # There are preexisting records that break this rule. We can't support
        # this requirement until those records are fixed
        if CNAME.objects.filter(fqdn=self.name).exists():
            raise ValidationError("PTR records must point back to a valid A "
                                  "record, not a alias defined by a CNAME."
                                  " -- RFC 1034")
Considering existing CNAMES must be done when editing and
dataset/ETHPy150Open rtucker-mozilla/mozilla_inventory/mozdns/ptr/models.py/PTR.validate_no_cname