namespace Common
{
    /// <summary>
    /// Marker interface for commands.
    /// </summary>
    public interface ICommand<in TRequest> where TRequest : IRequest
    {
        void Execute(TRequest request);
    }
}

namespace Common
{
    /// <summary>
    /// Marker interface for requests.
    /// </summary>
    public interface IRequest
    {
    }
}