using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using System;

public class Program

{

    public static void Main()

    {

        var item = JObject.Parse("{ 'str1': 'test1' }");

        Console.WriteLine("Original Parsed:");

        Console.WriteLine(item.ToString(Formatting.Indented));

        Console.WriteLine();

        item["str1"] = "test2";

        Console.WriteLine("Overwritten Property Value:");

        Console.WriteLine(item.ToString(Formatting.Indented));

        Console.WriteLine();

        item["str3"] = "test3";

        Console.WriteLine("Newly Added Property:");

        Console.WriteLine(item.ToString(Formatting.Indented));

    }

}