A ProductPackageItem represents a product which will be associated with
a ProductPackage.
To use this service, you need to have the new sales
management solution enabled on your network. If you do not see a "Sales"
tab in <a href="https://www.google.com/dfp">DoubleClick for Publishers
(DFP)</a>, you will not be able to use this service.
createProductPackageItems
Creates new ProductPackageItem objects.