using System.Text.Json;

using System.Text.Json.Serialization;

using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        var json = @"

            {

              ""doot"": ""bloop bloop"",

              ""bars"": 

              [

                {

                    ""id"": 1

                },

                {

                    ""id"": 2

                }

              ]

            }

        ";

        var obj = JsonSerializer.Deserialize<Foo>(json);

        Console.WriteLine($"obj.Doot: {obj.Doot}");

        if (obj.Bars == null)

            Console.WriteLine("Bars is null.");

        else

        {

            obj.Bars.Add(new Bar(){ Id = 42 });

            Console.WriteLine($"obj.Bars.Count: {obj.Bars.Count}");

            foreach (var item in obj.Bars)

            {

                Console.WriteLine($"Id: {item.Id}");

            }

        }

    }

    public class Foo

    {

        private string _doot;

        [JsonPropertyName("doot")]

        public string Doot

        {

            get => _doot;

            set

            {

                Console.WriteLine($"Setting Doot to {value}");

                _doot = value;

            }

        }

        private List<Bar> _bars;

        [JsonPropertyName("bars")]

        public List<Bar> Bars 

        {

            get => _bars;

            set

            {

                Console.WriteLine($"Bars Value count during setter: {value.Count}");

                _bars = value;

            }

        }

    }

    public class Bar

    {

        [JsonPropertyName("id")]

        public int Id {get;set;}

    }

}