ApprovalTests.Reporters.GenericDiffReporter.AssertDots C# (CSharp) Method

        private static void AssertDots(string[] extensionsWithDots)
        {
            var wrong = extensionsWithDots.Where(s => !s.StartsWith("."));
            if (wrong.Count() > 0)
            {
                throw new ArgumentException("The following extensions don't start with dots: " +
                                            wrong.ToReadableString());
            }
        }