如何在Spring.NET中处理null请求范围对象

I have a couple of objects in Spring.NET that I have created in the request scope. This works fine when the instance exists but sometimes they need to be null. If I return null from the factory that creates them I get an error from Spring.NET indicating that it cannot wrap a null object. I gather it is trying to create a proxy around the object and failing to do so since it is null.I have a couple of objects in Spring.NET that I