Domain Model和UI Model转换extension Method

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ConsoleApplication3
{
    class Program
    {
        static void Main(string[] args)
        {
            BookModel a=new BookModel();
            a.ToDomainModel();
            BookDomainModel b =new BookDomainModel();
            b.ToModel();
        }
    }

    public class BookModel
    {
        public int Id { get; set; }
        public string Name { get; set; }
    }

    public class BookDomainModel
    {
        public int Id { get; set; }
        public string Name { get; set; }

    }

    public static class MappingExtension
    {
        // convert the adapter domain model to prensentation model
        public static BookModel ToModel(this BookDomainModel domainModel)
        {
            var model = new BookModel();
            // to do mapping

            return model;
        }

        // convert the UI model to Domain model
        public static BookDomainModel ToDomainModel(this BookModel model)
        {
            var domain = new BookDomainModel();
            // to do mapping

            return domain;
        }
    }
}