using System;

using Moq;

public class Program

{

    public static void Main()

    {

        var mock = new Mock<IRepository<object, int>>();

        mock.SetupGet(x => x.Foo).Returns(new Foo<object>());

        var service = new Service<object, int>(mock.Object);

        Console.WriteLine(mock.Object.Foo.GetHashCode());

        Console.WriteLine(service.Foo.GetHashCode());

    }

    public interface IRepository<T>

    {

        Foo Foo { get; set; }

    }

    public interface IRepository<T, TK> : IRepository<T>

    {

        new Foo<T> Foo { get; set; }

    }

    public class Service<T>

    {

        public IRepository<T> Repository { get; set; }

        public Foo Foo { get; set; }

        public Service(IRepository<T> repository)

        {

            Repository = repository;

            Foo = repository.Foo;

        }

    }

    public class Service<T, TK> : Service<T>

    {

        public new IRepository<T, TK> Repository 

        {

            get { return (IRepository<T, TK>)base.Repository; }

            set { base.Repository = value; }

        }

        public Service(IRepository<T, TK> repository) : base(repository)

        {

        }

    }

    public class Foo

    {

        public int Id { get; set; }

    }

    public class Foo<T> : Foo

    {

    }

}