using System;

using ExtendedXmlSerialization;

​

public class Program

{

    public interface IEngine

    {

        string Name {get;set;}

    }

    public class Car

    {

        public IEngine Engine {get;set;}

    }

​

    public class ElectricEngine : IEngine 

    {

        public string Name {get;set;}

        public int batteryPrecentageLeft {get;set;}

    }

    public class InternalCombustionEngine : IEngine 

    {

        public string Name {get;set;}

        public int gasLitersLeft  {get;set;}

    }

    public static void Main()

    {

        Car myCar = new Car();

        myCar.Engine = new ElectricEngine() {batteryPrecentageLeft= 70, Name = "turbo diesel"};

        var serializer = new ExtendedXmlSerializer();

        var xml = serializer.Serialize(myCar);

        Console.WriteLine(xml);

    }

}