Indeed, but we could use that superclass directly since there's a subclass is adding, see Moneybookers' ``#return`` ([link](https://github.com/Shopify/active_merchant/blob/2984bac0a563502bb89d7024c60ce9f9aca70606/lib/active_merchant/billing/integrations/moneybookers.rb#L20-L22)) for an example.

https://github.com/Shopify/active_merchant/blob/2984bac0a563502bb89d7024c60ce9f9aca70606/lib/active_merchant/billing/integrations/return.rb