using System;

public class Program

{

    public static void Main()

    {

        var stringContent = "{}";

        Newtonsoft.Json.Linq.JObject content = Newtonsoft.Json.Linq.JObject.Parse(stringContent);

        if (content.ContainsKey("Test"))

        {

            //continue; 

        }

        content.Add(new Newtonsoft.Json.Linq.JProperty("Test", "blah blah"));

        //content.Add(("Test2", "blah blah"));

        Console.WriteLine(content.ToString(Newtonsoft.Json.Formatting.Indented));

        Console.WriteLine(Newtonsoft.Json.JsonConvert.SerializeObject(content, Newtonsoft.Json.Formatting.Indented));

    }

}