AddToCartPostHandler.cs

public class AddToCartPostHandler : IRequestPostProcessor<AddToCart, Unit>
{
    private readonly ILogger<AddToCart> _logger;

    public AddToCartPostHandler(ILogger<AddToCart> logger)
    {
        _logger = logger;
    }
    public Task Process(AddToCart request, Unit response)
    {
        _logger.LogInformation("Album {albumId} was added to the cart.", request.AlbumId);
        return Task.FromResult(0);
    }
}