using System;

namespace JustMyTests
{
    class Program
    {
        static void Main(string[] args)
        {
            var p = new MyPresenter();
            Presenter ip = p; // error!
        }
    }

    interface IModel
    {
    }

    interface IPresenter<in T>
        where T : class, IModel
    {
        void SomeMethod(T t);
    }

    class Presenter
    {

    }

    abstract class Presenter<T> : Presenter, IPresenter<T>
        where T : class, IModel
    {
        public abstract void SomeMethod(T t);
    }

    class MyModel : IModel
    {
    }

    class MyPresenter : Presenter<MyModel>
    {
        public override void SomeMethod(MyModel t)
        {
            Console.WriteLine("Hello!");
        }
    }
}