How do I handle null nested objects in RDLC report that is bound to custom assembly object datasource?

Question

I have an RDLC report that I am rendering directly to the Response Stream as PDF (rather than using the ReportViewer). In the code that renders the report, it\'s DataSource is

Answer 1

=iif(First(Fields!model.Value, "model") Is Nothing, "value is NULL", "value is not NULL")