public void ShouldSortNumberStringArray()
        {
            var sorter = CreateSorter <FileLine>(new FileLineSizeCalculator());

            var sourceArray = new FileLine[]
            {
                FileLine.Parse("415. Apple"),
                FileLine.Parse("30432. Something something something"),
                FileLine.Parse("1. Apple"),
                FileLine.Parse("32. Cherry is the best"),
                FileLine.Parse("2. Banana is yellow")
            };
            var expectedArray = new FileLine[]
            {
                FileLine.Parse("1. Apple"),
                FileLine.Parse("415. Apple"),
                FileLine.Parse("2. Banana is yellow"),
                FileLine.Parse("32. Cherry is the best"),
                FileLine.Parse("30432. Something something something")
            };

            var sortedArray = sorter.Sort(sourceArray);

            CollectionAssert.AreEqual(expectedArray, sortedArray);
        }