    # File lib/active_merchant/billing/gateways/payment_express.rb, line 46
          def purchase(money, payment_source, options = {})

            credit_card = payment_source if payment_source.respond_to?(:number)

            if credit_card
              options[:credit_card] = credit_card
            else
              options[:token]       = payment_source
            end

            request = build_purchase_or_authorization_request(money, options)
            commit(:purchase, request)
          end