We should definitly discuss the order <-> payment details relation problem. 

#### First I want to clarify

Payum  does not provide unifiy payment model in any way. All of them payment specific, do not share any interfaces or parent classes. For paypal rest situation even better: we reuse thier offical model that comes with `paypal/rest-api-sdk`. The bridge for jms plugings works with its `PaymentInstruction` model. So it is a chanlage to unify th

#### So how I did it

We have `Order` to `PaymentDetails` realtion (Order is owning side). Let's say one-to-one. `PaymentDetails` model implements class table inheritance pattern. There should be a way to dynamiclly add new classes to the map. I think it is possible with metadata doctrine event. I used this strategy in several projects: works fine but I dont think it is the best for the e-comerrace platform. 

What do you thinnk?