setReaderDisplay
Updates the reader display with transaction information. This method is for display purposes only and has no correlation with what the customer is actually charged. Tax and total are also not automatically calculated and must be set in Cart.
See https://stripe.com/docs/terminal/checkout/cart-display#set-the-reader-display
Parameters
cart
The Cart containing the transaction information to display on the reader screen
callback
The callback to be called when the operation completes