gistfile1.cs

        public static AutoMappingExpression Override<TController>(this AutoMappingExpression autoMappingExpression, string url, Expression<Action<TController>> actionExpression)
        {
            Assert.ParameterIsNotNull(autoMappingExpression, "mappingExpression");
            Assert.ParameterIsNotNull(url, "url");

            var methodCallExpression = actionExpression.Body as MethodCallExpression;

            if (methodCallExpression == null)
            {
                throw new ArgumentException("Invalid expression. Expression should consist of a Method call only.");
            }

            var controllerType = typeof(TController);
            var actionType = methodCallExpression.Method;

            return autoMappingExpression.AddOverride(controllerType, actionType, url);
        }