op() :: :Purchase

t() :: %SwedbankpayCheckout.Model.PaymentOrder{
  amount: Integer.t(),
  created: String.t(),
  currency: SwedbankpayCheckout.Model.Currency.t(),
  current_payment: SwedbankpayCheckout.Model.LoadableUrl.t(),
  description: String.t() | nil,
  id: String.t(),
  initiating_system_user_agent: String.t(),
  items: [SwedbankpayCheckout.Model.Item.t()],
  language: SwedbankpayCheckout.Model.Language.t(),
  operation: op(),
  order_items: SwedbankpayCheckout.Model.LoadableUrl.t(),
  payee_info: SwedbankpayCheckout.Model.LoadableUrl.t(),
  payments: SwedbankpayCheckout.Model.LoadableUrl.t(),
  state: SwedbankpayCheckout.Model.PaymentOrderState.t(),
  updated: String.t(),
  urls: SwedbankpayCheckout.Model.LoadableUrl.t(),
  user_agent: String.t() | nil,
  vat_amount: Integer.t()
}