public void Publish()
        {
            currentSerialNumber++;
            var newspaper = new Newspaper(currentSerialNumber, "HOT NEWS", "The New York Times Bla-bla-bla...");

            NewspaperPublished?.Invoke(newspaper);
        }
        public void Publish()
        {
            currentSerialNumber++;
            var newspaper = new Newspaper(currentSerialNumber, "HURRY TO READ!", "The Times Bla-bla-bla...");

            NewspaperPublished?.Invoke(newspaper);
        }