using System;

using System.Xml;

public class Program

{

    public static void Main()

    {

        var xml = @"<root><items><item id=""1"">item 1</item><item id=""2"">item 2</item></items></root>";

        var xmlDoc = new XmlDocument();

        xmlDoc.LoadXml(xml);        

        Console.WriteLine($"Xml: {xml}");

        Console.WriteLine($"XmlDocument xml: {xmlDoc.ToString()}");

        var serializedXml = System.Text.Json.JsonSerializer.Serialize(xmlDoc);

        Console.WriteLine($"Serialized xml using System.Text.Json: {serializedXml}");

        serializedXml = Newtonsoft.Json.JsonConvert.SerializeObject(xmlDoc);

        Console.WriteLine($"Serialized xml using Newtonsoft.Json: {serializedXml}");

    }

}