public static class ControllerExtensions    {        private static readonly Regex m_regex = new Regex(@"(?<=[^])\t{2,}|(?<=[>])\s{2,}(?=[<])|(?<=[>])\s{2,11}(?=[<])|(?=[\n])\s{2,}");        public static string RenderView(this Controller controller, string viewName, object model, string master = null)        {            var vd = new ViewDataDictionary();            foreach (var item in controller.ViewData.Keys)            {                vd.Add(item, controller.ViewData[item]);            }            vd.Model = model;            using (StringWriter sw = new StringWriter())            {                ViewEngineResult viewResult = ViewEngines.Engines.FindView(controller.ControllerContext, viewName, master);                ViewContext viewContext = new ViewContext(controller.ControllerContext, viewResult.View, vd, controller.TempData, sw);                viewResult.View.Render(viewContext, sw);                return m_regex.Replace(sw.GetStringBuilder().ToString(), string.Empty);            }        }    }