public string markAsException(string fragment, string expression, string errorMessage)
        {
            var exception = new StackTraceSettingException(errorMessage);
            exception.StackTraceElements.AddRange(stackTraceElements);

            var document = new TestRig()
                                .ProcessFragment(fragment)
                                .GetXDocument();

            var element = new Element(document.Descendants("p").ToArray()[0]);

            new ExceptionRenderer().ExceptionCaught(new ExceptionCaughtEvent(exception, element, expression));

            return element.ToXml();
        }
        public string markAsException(string fragment, string expression, string errorMessage)
        {
            var exception = new StackTraceSettingException(errorMessage);
            exception.StackTraceElements.AddRange(stackTraceElements);

            var document = new TestRig()
                                .ProcessFragment(fragment)
                                .GetXDocument();

            var element = document.Descendants("p").ToArray()[0];

            var eventArgs = new ExceptionCaughtEventArgs { Exception = exception, Expression = expression, Element = new Element(element) };
            new ExceptionRenderer().ExceptionCaughtEventHandler(this, eventArgs);

            //return element.ToString(SaveOptions.DisableFormatting);
            return element.ToString();
        }