using System;

using AutoFixture;

using AutoFixture.Kernel;

public class Program

{

    public static void Main()

    {

        var fixture = new Fixture();

        fixture.Customizations.Add(new TypeRelay(typeof(ILamp),typeof(Lamp)));

        fixture.Customize<Lamp>(

            c => c.With(x => x.IsWorking, true)

                  .With(x => x.LampModel));

        var actual = fixture.Create<MyClass>();

        Console.WriteLine(actual.Lamp.IsWorking);

        Console.WriteLine(actual.Lamp.LampModel);

    }

}

​

public interface ILamp

{

    bool IsWorking { get; set; }

​

    string LampModel { get; set; }

}

​

public class Lamp : ILamp

{

    private string _lampModel;

    public bool IsWorking { get; set; }

​

    public string LampModel { 

        get => _lampModel;

        set { _lampModel = IsWorking ? value : throw new Exception("its not in working."); }

    }

}

​

public class MyClass

{

    public ILamp Lamp {get;set;}

}