public void ToXml()
        {
            XmlDocument doc = new XmlDocument();
            var bookMark = new NumberBookmark();
            bookMark.FileName = "TestFile.cs";
            bookMark.LineNumber = 29;
            bookMark.Column = 10;
            bookMark.BookmarkType = BookmarkType.Global;
            bookMark.Number = 4;
            XmlElement element = bookMark.ToXml(doc);

            StringBuilder builder = new StringBuilder();
            XmlWriterSettings settings = new XmlWriterSettings();
            settings.Indent = false;
            settings.Encoding = Encoding.UTF8;
            settings.OmitXmlDeclaration = true;
            XmlWriter writer = XmlWriter.Create(builder, settings);
            element.WriteTo(writer);
            writer.Flush();
            string value = "<NumberBookmark Type=\"1\" Number=\"4\" FileName=\"TestFile.cs\" LineNumber=\"29\" Column=\"10\" />";
            Assert.AreEqual(value, builder.ToString());
        }