Validate a PaymentMethod that is already attached to a Company. Please note that only bank PaymentMethods can be validated at this time.

When testing in the Routable Sandbox, you can deterministically control the results you wish to receive for
each check based on the values of the last two digits of the account_number (when creating the original PaymentMethod).

Pass the following number in a check's digit to get the result you want:
1: match
2: mismatch
3: no_data
4: unable_to_verify
5-9 and 0: result undefined