This only exists because a provider collection can never be empty

This only exists because a provider collection can never be empty

This provider does nothing. It exists only because there must always be at least one provider in the collection or an error occurs.

This is just a stub that you can copy for a starting point in implementing new gateways

PayPal Express Checkout Flow: Call SetExpressCheckout to get a token then redirect to paypal with the token. When PayPal redirects back to your landing page you make a server side request with GetExpressCheckoutDetails passing the token and PalPal respond swith the payment status and details. On success you can either give the user a final chance to review the order or just make the DoExpressCheckoutPayment request to PayPal and process the order In either case you make the same call but if you want the user to review the order again then do it from a user button click