| def save(self, *args, **kwargs): | |
| subCount = sum([1 for e in [self.subscriber_service, self.subscriber_service_instance, self.subscriber_network] if e is not None]) | |
| if (subCount > 1): | |
| raise XOSConflictingField( | |
| "Only one of subscriber_service, subscriber_service_instance, subscriber_network should be set") | |
| super(ServiceInstanceLink, self).save(*args, **kwargs) | |