Json.Netでのデシリアライズの確認

json.cs

using Newtonsoft.Json;
using System;
using System.Collections.Generic;

namespace JsonDemo
{
    class Program
    {
        public static void Main(string[] arg)
        {
            var x = new Test();

            x.Items.Clear();
            x.Items.Add(6);

            var json = JsonConvert.SerializeObject(x);

            var y = JsonConvert.DeserializeObject<Test>(json);
            foreach (var i in y.Items)
            {
                System.Diagnostics.Debug.Write(i.ToString() + ",");
                // -> 1,2,3,4,5,6,
            }
            System.Diagnostics.Debug.WriteLine("");


            var settings = new JsonSerializerSettings
            {
                ObjectCreationHandling = ObjectCreationHandling.Replace,
            };
            var z = JsonConvert.DeserializeObject<Test>(json, settings);
            foreach (var i in z.Items)
            {
                System.Diagnostics.Debug.Write(i.ToString() + ",");
                // -> 6,
            }
            System.Diagnostics.Debug.WriteLine("");
        }

        public class Test
        {
            public IList<int> Items { get; set; } = new List<int> { 1, 2, 3, 4, 5 };
        }
    }
}