public void AddXhtml11()
        {
            var xmlResolver = new XmlPreloadedResolver();

            xmlResolver.AddXhtml11();
            EnumerableAssert.Contains(xmlResolver.PreloadedUris, new Uri(Xhtml11.DtdPublicId, UriKind.RelativeOrAbsolute));
            EnumerableAssert.Contains(xmlResolver.PreloadedUris, new Uri(Xhtml11.DtdSystemId, UriKind.RelativeOrAbsolute));
        }
        public void AddXhtml11_XDocument()
        {
            var xmlResolver = new XmlPreloadedResolver();

            xmlResolver.AddXhtml11();

            XmlReaderSettings settings = new XmlReaderSettings();

            settings.DtdProcessing = DtdProcessing.Parse;
            settings.XmlResolver   = xmlResolver;

            XDocument document;

            using (var stringReader = new StringReader(sampleXhtml))
                using (var xmlReader = XmlReader.Create(stringReader, settings))
                    document = XDocument.Load(xmlReader);

            XNamespace ns   = "http://www.w3.org/1999/xhtml";
            var        span = document.Descendants(ns + "span").Single();

            Assert.AreEqual(" ®µ½Σ", span.Value);
        }