title: How to have a blendable project using MVVM-Light and WCF RIA Services
body: <p>I'd like to build my business application using the MVVM pattern. I choose MVVM-Light because it fits to my needs.
  In every example I've seen about MVVM-Light, no-one use the WCF RIA. The classic MIX10 example uses a Service in the same project while WCF RIA create a service in the Web project.
  The question is: it looks very hard to build an interface of the whole DomainContex the WCF Ria creates (it is surely hard for me!) but without an interface how could I build a fake DomainContex to be used in Blend and in tests as well?
  Am I missing something?
  Thanks.</p>