This snippet <!--Please don't delete this--> is part of my xml file. After running this method, the resulting xml file does not contain this snippet anymore <!--Please don't delete this-->. Why is this?

Here's my method:

         XmlSerializer serializer = new XmlSerializer(typeof(Settings));
         TextWriter writer = new StreamWriter(path);
         serializer.Serialize(writer, settings);
         writer.Close();