handler.cs

public class AlbumAddedToCartHandler 
    : INotificationHandler<AlbumAddedToCart>
{
    private readonly ILogger<AddToCart> _logger;

    public AlbumAddedToCartHandler(ILogger<AddToCart> logger)
    {
        _logger = logger;
    }

    public void Handle(AlbumAddedToCart notification)
    {
        _logger.LogInformation("Album {albumId} was added to the cart.",
            notification.AlbumId);
    }
}