public IEnumerable <T> IterTest01 <T>(IEnumerable <T> source, Action <T, int> action)
        {
            IEnumerable <T> result = EnumerableExtension.Iter <T>(source, action);

            return(result);
            // TODO: add assertions to method EnumerableExtensionTest.IterTest01(IEnumerable`1<!!0>, Action`2<!!0,Int32>)
        }