title: Stub a property which is in the concrete class but not on the interface for unit testing
body: <p>I have a class which has more information then my inteface. It has a property which I did not expose in my interface.</p>
  
  <pre><code> public interface IViewResolver
  {
      object GetViewFor(string viewName);
  
  }
  </code></pre>
  
  <p>I want now to implement a MefViewResolver based on that interface.</p>
  
  <pre><code>public class ViewResolver : IViewResolver
  {
  
  
      [ImportMany]
      public IEnumerable&lt;Lazy&lt;IView,IViewMetaData&gt;&gt; Views { get; set; }
  
  
  
      public object GetViewFor(string viewName)
      {
          var view = Views.Where(x =&gt; x.Metadata.Name == viewName).FirstOrDefault();
  
          return view == null ? null : view.Value;
      }
  
  }
  </code></pre>
  
  <p>My SUT gets a IResolver per constructor injection loaded with my mefViewResolver. In my unit test I would like to pre-set my Views property from the outside without using mef or being mef specific in my interface. 
  Basically I want to set the Views with an expected value and see if my viewmodel which uses the IViewResolver returns the preset view...
  How can I stub the views property even if it does not exists on my interface...</p>
  
  <p>If I am on the wrong path... any corrections would much appriciated..</p>
  
  <p>Thanks D.</p>