Creates a new, empty payment instrument object associated with the
related customer for the given payment method.
the id of a payment method
the new payment instrument object.
If passed 'paymentMethodId' is null.
Returns a collection of all payment instruments associated with the
related customer filtered by the given payment method id. If
null is passed as payment method id all payment instruments
of the customer will be retrieved. If for the given payment method id no
payment instrument is associated with the customer an empty collection
will be returned.
the paymentMethodID the payment method id to filter for
Collection of payment instruments for a payment method.
Removes a payment instrument associated with the customer.
the instrument associated with this customer
If passed 'instrument' is null.
If passed 'instrument' belongs to an other customer