Looking for full ActiveMerchant AuthorizeNetCimGateway documentation for options requirements

I am integrating ActiveMerchant in a project, and am mystified over and over again by the lack of documentation for the options parameter. Taking the following as an example, where do I locate information for what form/format the :payment hash or :payment_profile hash should take. What am I missing here?

create_customer_payment_profile(options)
Creates a new customer payment pro开发者_如何学Pythonfile for an existing customer profile.

Options
:customer_profile_id — The Customer Profile ID of the customer the payment profile will be added to. (REQUIRED)
:payment_profile — A hash containing the elements of the new payment profile (REQUIRED)
Payment Profile
:payment — A hash containing information on payment. Either :credit_card or :bank_account (REQUIRED)

I found the following on someone's blog, and I wonder how I would have been able to infer all of this from the sparse docs on ActiveMerchant. Plus the bill_to isn't even mentioned anywhere in the docs, and seems incomplete below:

@profile = {:customer_profile_id => self.user.customer_cim_id,
            :payment_profile => {:bill_to => self.address,
                                 :payment => {:credit_card => CreditCard.new(self.credit_card)}
                                 }