There is no way to add "object_purpose": "PURCHASE" to batch request.

I have received answer from support(Rodrigo) about my [issue](https://stackoverflow.com/questions/59072764/why-i-receive-carrier-does-not-exist-if-i-specify-carrier-account-in-request) with creating batch. He suggested to add "object_purpose": "PURCHASE" to `Address` and `Shipment` objects. But I don't see options to add it.
