我收到这样的错误：
#21915469 : At least one valid shipping service must be specified.
我正在使用的代码：
$ShippingServiceOptions = new ShippingServiceOptionsType();
$ShippingServiceOptions-> setShippingService('DE_InsuredDispatch');
$ShippingServiceOptions-> setShippingServiceCost('3.33');
$ShippingServiceOptions-> setShippingServiceAdditionalCost('2.5');
$ShippingServiceOptions-> setShippingServicePriority('1');
$shipping[]=$ShippingServiceOptions;