[1] Payment Method Manifest (2017-04-26 00:49:32 +09:00) <https://w3c.github.io/payment-method-manifest/#processing-model>
[2] Payment Method Manifest (2017-12-08 13:11:29 +09:00) <https://www.w3.org/TR/2017/WD-payment-method-manifest-20171212/>