def METHOD_NAME(self, pad_bbl_or_bin: str) -> None:
    regs = self._get_registrations(pad_bbl_or_bin)
    models: List[Any] = list(regs)
    for reg in regs:
        models.extend(reg.contact_list)
    data = json.loads(serializers.serialize("json", models))
    self.stdout.write(json.dumps(data, indent=2))