using System;

using System.Collections.Generic;

​

public interface IDomainEvent {}

public class ProductSetCreatedEvent : IDomainEvent {}

public class VersionCreatedEvent : IDomainEvent {}

​

public class ProductSetCreatedEventHandler : IDomainEventHandler<ProductSetCreatedEvent> {}

public class VersionCreatedEventHandler : IDomainEventHandler<VersionCreatedEvent> {}

​

public interface IDomainEventHandler<in TDomainEvent> where TDomainEvent : IDomainEvent {}

public interface IDomainEventHandler2 {}

​

public class ProductSetCreatedEventHandler2 : IDomainEventHandler2 {}

​

public interface IRegistry<in TDomainContraVariant>

    where TDomainContraVariant : IDomainEventHandler2

{

    void Add(TDomainContraVariant element);

}

​

​

public class Registry<TDomainContraVariant> : IRegistry<TDomainContraVariant>

    where TDomainContraVariant : IDomainEventHandler2

{

    private IList<IDomainEventHandler2> list;

​

    public Registry()

    {

        this.list = new List<IDomainEventHandler2>();

    }

​

    public void Add(TDomainContraVariant element)

    {

        this.list.Add(element);

    }

    public IList<IDomainEventHandler2> Get()

    {

        return this.list;

    }

}

public class Program

{   

    private static Registry<IDomainEventHandler2> list = new Registry<IDomainEventHandler2>();

    public static void Main()

    {       

        IDomainEventHandler2 eventHandler = new ProductSetCreatedEventHandler2();

        AddToRegistry<IDomainEventHandler2>(eventHandler);

    }

    public static void AddToRegistry<TDomainContraVariant>(TDomainContraVariant cesto)

        where TDomainContraVariant : IDomainEventHandler2

    {

        list.Add(cesto);

    }

}