// CS738: `CB' does not implement interface member `IG<IA>.Method()' and the best implementing candidate `CA<IB>.Method()' return type `IB' does not match interface member return type `IA' // Line: 29 public interface IA { } public interface IB : IA { } public interface IG<out U> { U Method (); } public interface IDerived : IG<IA> { } public abstract class CA<T> : IG<T> { public T Method () { return default (T); } } public class CB : CA<IB>, IG<IA> { }