CommandHandler classes

CommandHandler.cs

public abstract class CommandHandler<TCommand, TResult> where TCommand : ICommand<TResult>
{
    public abstract TResult Handle(TCommand command);
}

public class SomeCommandeHandler : CommandHandler<SomeCommand, Guid>
{
    public override Guid Handle(SomeCommand command)
    {
        // Do stuff here
        return Guid.NewGuid();
    }
}

public class SimpleInjectorCommandHandlerResolver : ICommandHandlerResolver
{
    private readonly Container _container;

    public SimpleInjectorCommandHandlerResolver(Container container)
    {
        _container = container;
    }

    public CommandHandler<ICommand<TResult>, TResult> ResolveForCommand<TResult>(ICommand<TResult> command)
    {
        var handlerType = typeof(CommandHandler<,>).MakeGenericType(command.GetType(), typeof(TResult));
        return (CommandHandler<ICommand<TResult>, TResult>) _container.GetInstance(handlerType);
    }
}