# Example: serializer that will break after #8979classBankBulkUpdateSerializer(serializers.ListSerializer):"""Bank bulk update serializer."""defupdate(self,instance:models.QuerySet[Bank],validated_data:list[OrderedDict],    )->list[Bank]:"""Bulk update banks."""bank_dict= {bank.pk:bankforbankininstance}banks_to_create:list[Bank]= []banks_to_update:list[Bank]= []banks_created:list[Bank]= []banks_updated:list[Bank]= []bank_pks_to_keep:list[int]= []forbank_datainvalidated_data:bank_id=bank_data.get("id")bank=bank_dict.get(bank_id)ifbank_idisnotNoneelseNoneifbankisnotNone:forattr,valueinbank_data.items():setattr(bank,attr,value)banks_to_update.append(bank)bank_pks_to_keep.append(bank.pk)else:bank=Bank(**bank_data)banks_to_create.append(bank)withdb_transaction.atomic():instance.exclude(pk__in=bank_pks_to_keep).delete()ifbanks_to_update:update_fields= ["name","compe","ispb","website"]Bank.objects.bulk_update(banks_to_update,update_fields)banks_updated=banks_to_updateifbanks_to_create:banks_created:list[Bank]=Bank.objects.bulk_create(banks_to_create                )returnsorted(banks_created+banks_updated,key=lambdaa:a.name)