when<TResult extends Object?>  method 
- @optionalTypeArgs
- TResult $default(- String? accountNumber,
- String? routingNumber,
- UsBankAccountHolderType? accountHolderType,
- UsBankAccountType? accountType,
- BillingDetails? billingDetails,
- ShippingDetails? shippingDetails,
 
A switch-like method, using callbacks.
As opposed to map, this offers destructuring.
It is equivalent to doing:
switch (sealedClass) {
  case Subclass(:final field):
    return ...;
  case Subclass2(:final field2):
    return ...;
}
Implementation
@optionalTypeArgs TResult when<TResult extends Object?>(TResult Function( String? accountNumber,  String? routingNumber,  UsBankAccountHolderType? accountHolderType,  UsBankAccountType? accountType,  BillingDetails? billingDetails,  ShippingDetails? shippingDetails)  $default,) {final _that = this;
switch (_that) {
case _PaymentMethodDataUsBank():
return $default(_that.accountNumber,_that.routingNumber,_that.accountHolderType,_that.accountType,_that.billingDetails,_that.shippingDetails);case _:
  throw StateError('Unexpected subclass');
}
}