using System;

using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

​

        var bse = JsonConvert.DeserializeObject<MutablePropertyStore>("{ 'PropertyB' : true }");

        Console.WriteLine("Base:    " +  bse.ToString());   

        var derived = new ImmutablePropertyStore(bse);

        Console.WriteLine("Derived: " + derived.ToString());    

​

    }

}

​

public sealed class ImmutablePropertyStore : MutablePropertyStore

{

    public new bool PropertyA { get; private set; }

    public new bool PropertyB { get; private set; }

    public ImmutablePropertyStore() { }

    public ImmutablePropertyStore(MutablePropertyStore ms)

    {

        PropertyA      = ms.PropertyA;

        this.PropertyB = ms.PropertyB;

    }

    public ImmutablePropertyStore(bool propertyA = true, bool propertyB = false)

    {

        PropertyA = propertyA;

        PropertyB = propertyB;

    }

    public override string ToString() 

        => $"Property A is '{PropertyA}' and Property B is '{PropertyB}'."; 

}

​

public class MutablePropertyStore

{

    public virtual bool PropertyA { get; set;}

    public virtual bool PropertyB { get; set;}

​

    // Set all defaults here

    public MutablePropertyStore() {  }

​

    public override string ToString() 

        => $"Property A is '{PropertyA}' and Property B is '{PropertyB}'.";      

​

}