Program.cs

/* In this example, the Book class implements the IPrototype<T> interface, 
 * allowing Book instances to be cloned. The BookCache class manages a cache of these books. 
 * When a book is requested, the cache checks if it already has the book; if so, it returns a clone,
 * avoiding the need to refetch the book from the database. This demonstrates how the Prototype pattern 
 * can be effectively used to cache and efficiently reuse complex objects like the results of database calls. */

BookCache cache = new BookCache();

// Fetch a book for the first time
Book book1 = cache.GetBook(123456);
Console.WriteLine($"Retrieved book: {book1.Title} by {book1.Author}");

// Fetch the same book again, this time it should come from the cache
Book book2 = cache.GetBook(123456);
Console.WriteLine($"Retrieved book: {book2.Title} by {book2.Author}");

// Verify that a clone was returned
Console.WriteLine($"Are book1 and book2 the same instance? {(book1 == book2 ? "Yes" : "No")}");