endpoint.cs

        public class InputQueryModel
        {
            public string Name { get; set; }
        }

        public class InputCommandModel : InputQueryModel
        {
        }

        public class Endpoint
        {
            public InputQueryModel Query(InputQueryModel input)
            {
                return new InputQueryModel();
            }

            public AjaxContinuation Command(InputCommandModel input)
            {
                Debug.Assert(input.Name.IsEmpty()); // FAILS!
                return AjaxContinuation.Successful();
            }
        }


        public class InputCommandModelRules : OverridesFor<InputCommandModel>
        {
            public InputCommandModelRules()
            {
                // This wont be picked up
                Property(x => x.Name).Required();
            }
        }