module Stripe class Card < APIResource include Stripe::APIOperations::Update include Stripe::APIOperations::Delete include Stripe::APIOperations::List def url "#{Customer.url}/#{CGI.escape(customer)}/cards/#{CGI.escape(id)}" end def self.retrieve(id, api_key=nil) raise NotImplementedError.new("Cards cannot be retrieved without a customer ID. Retrieve a card using customer.cards.retrieve('card_id')") end end end