public void CanEnumerateNested()
        {
            const string input        = "asdf";
            var          sut          = new StringInput(input);
            int          visitedItems = 0;

            foreach (var outerItem in sut.GetEnumerable(0))
            {
                var innerItem = sut.GetEnumerable(visitedItems, 1).ToList().Single();
                Assert.AreEqual(outerItem, innerItem);
                visitedItems += 1;
            }
            Assert.AreEqual(input.Length, visitedItems);
        }
        public void CanEnumerateString()
        {
            var sut = new StringInput("asdf");

            CollectionAssert.AreEqual("asdf".ToCharArray(), sut.GetEnumerable(0));
        }