public void AddBook(string isbn, string code, string title, string author, string subject)
{
Book newBook;
using (var cli = new BookServiceClient())
{
cli.Open();
newBook = cli.CreateBook(isbn, code, title, author, subject);
cli.Close();
}
if (newBook != null)
{
books.TryAdd(newBook.Id, newBook);
}
}