//All instances of books/other media are instantiated within the Catalog constructor
public Catalog()
{
Books = CatalogToDisk.GenerateBookListFromDisk();
CDs = CatalogToDisk.GenerateMusicCdListFromDisk();
Magazines = CatalogToDisk.GenerateMagazineListFromDisk();
Medias = new List <Media>();
Medias.AddRange(Books);
Medias.AddRange(Magazines);
Medias.AddRange(CDs);
}
