using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

}

public interface IItem 

{ 

    int Id { get; set; }

}

​

public interface IGenerator

{

    IList<IItem> Generate();

}

​

​

public class ItemA : IItem 

{

    public int Id { get; set; }

    public string Name { get; set; }

}

​

public class ItemAGenerator : IGenerator

{

    public IList<IItem> Generate()

    {

        // do stuff

        var v = new List<ItemA>();

        return (IList<IItem>) v;

    }

}