public int TotalPrice(string commaSeparatedTrackCodes)
        {
            var trackCodes = new TrackCodes(commaSeparatedTrackCodes);

            return(trackCodes.Price());
        }
 public int TotalPrice(string commaSeparatedTrackCodes)
 {
     var trackCodes = new TrackCodes(commaSeparatedTrackCodes);
     return trackCodes.Price();
 }