static void Main(string[] args) { var client = new LibraryClient(); client.AddBook(new Book { Id = 10, Title = "Harry Potter10", Author = "J.Rouling", Year = 2000, Type = BookType.Fiction }); Book book = client.GetBookById(0); Book[] books = client.GetBooksByAuthor("J.Rouling"); Book takenBook = client.GiveBook(0, 0); client.ReturnBook(0, 0); Console.Write("I'am client of Library"); Console.ReadLine(); }