private static void apply <T>(IEnumerable <IContentExtension <T> > extensions, IFubuPage <T> page, string tag) where T : class
        {
            var extensionOutput = extensions.SelectMany(ex => ex.GetExtensions(page)).Where(o => o != null).ToArray();

            if (extensionOutput.Length == 0 && page.Get <DiagnosticsIndicator>().IsDiagnosticsEnabled)
            {
                page.Write("<!-- Content extensions '{1}' for {0} would be rendered here -->".ToFormat(typeof(T).Name, tag));
            }
            extensionOutput.Each(o => page.Write(o));
        }
        private static IHtmlString apply <T>(IEnumerable <IContentExtension <T> > extensions, IFubuPage <T> page, string tag)
            where T : class
        {
            var extensionOutput = extensions.SelectMany(ex => ex.GetExtensions(page)).Where(o => o != null).ToArray();

            if (extensionOutput.Length == 0 && FubuMode.InDevelopment())
            {
                page.Write("<!-- Content extensions '{1}' for {0} would be rendered here -->".ToFormat(typeof(T).Name,
                                                                                                       tag));
            }

            var output = new StringBuilder();

            extensionOutput.Each(o => output.Append(o).AppendLine());

            return(new HtmlString(output.ToString()));
        }