System.Tests.StringTests.AllSubstringsAndComparisons C# (CSharp) Method

        public static IEnumerable<object[]> AllSubstringsAndComparisons(string source)
        {
            var comparisons = new StringComparison[]
            {
            StringComparison.CurrentCulture,
            StringComparison.CurrentCultureIgnoreCase,
            StringComparison.Ordinal,
            StringComparison.OrdinalIgnoreCase
            };

            foreach (StringComparison comparison in comparisons)
            {
                for (int i = 0; i <= source.Length; i++)
                {
                    for (int subLen = source.Length - i; subLen > 0; subLen--)
                    {
                        yield return new object[] { source, source.Substring(i, subLen), i, comparison };
                    }
                }
            }
        }