Issue With Isolate.WhenCalled()

Hello,

I experience an issue with Isolate.WhenCalled. Suppose I have, in assembly A, a class that does:

public class MyCollection<T> : IList<T>
{
public virtual void Add(T item) { .. }

.
.
}

Assembly B references assembly A, and defines:

public class NewCollection : MyCollection<NewObj>
{

}

Notice it does not override Add. When I do in a test:


[Test]
public void TestColl()
{
var coll = Isolate.Fake.Instance<NewCollection>();
Isolate.WhenCalled(() => coll.Add(null)).CallOriginal();
}

This throws an exception. I don't have the stack trace handy, but it was looking for a reference to the method in a generic dictionary, and it couldn't find it. However, if in NewCollection i override the Add method (and simply return the base implementation), then this works fine.

Why is that?

Thanks.