Issue qualifying an generic interface

I created and generic interface and a class implements this interface twice.

public class MyClass: IMyInterface<Class1>, IMyInterface <Class2>
{
       List<Class1> IMyInterface<Class1>.MyMethod()
       {
           throw new NotImplementedException();
       }

       List<Class2> IMyInterface<Class2>.MyMethod()
       {
           throw new NotImplementedException();
       }
}

This works fine so far.

Now I am getting stuck when try to call one of the Methods. I tried:

MyClass myobject = new MyClass();
myobject.MyInterace<Class2>.MyMethod()