using System;

using System.Xml;

using System.Xml.Linq;

using System.Text.Json;

using System.Text.Json.Serialization;

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>";

        XDocument xmlDoc = XDocument.Parse(xml);        

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

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

            JsonSerializerOptions options = new()

            {

                ReferenceHandler = ReferenceHandler.IgnoreCycles,

                WriteIndented = true

            };

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

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

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

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

    }

}