<PartNotDiscoverableAttribute()>
Public MustInherit Class BaseCompositionContextResolver 
   Implements ICompositionContextResolver 

Dim instance As BaseCompositionContextResolver

[PartNotDiscoverableAttribute()]
public abstract class BaseCompositionContextResolver : ICompositionContextResolver  

[PartNotDiscoverableAttribute()]
public ref class BaseCompositionContextResolver abstract : public ICompositionContextResolver  

// Sample BaseCompositionContextResolver sub-type providing static fields defining CompositionContexts.
public class CompositionContextResolver : BaseCompositionContextResolver {
 
  public static CompositionContext Mock = new CompositionContext("MyMock", true,
    typeof(MockEntityServerSaveInterceptor), typeof(MockEntityServerQueryInterceptor));
}
 
// Sample class - note it is marked as not discoverable so that standard MEF
// composition will not find it.
[PartNotDiscoverable]
public class MockEntityServerQueryInterceptor : EntityServerQueryInterceptor {

   protected override bool ExecuteQuery() {
      throw new InvalidOperationException();
   }
}
[PartNotDiscoverable]
public class MockEntityServerSaveInterceptor : EntityServerSaveInterceptor {

   protected override bool  ExecuteSave() {
      throw new InvalidOperationException();
   }
}