// DELETE api/<controller>/5
        public void Delete(int userId, long bookId)
        {
            WaitingBooks wb = new WaitingBooks();

            long[] books = wb.GetBooksFromList(userId);
            wb.DeleteFromList(userId, bookId, books);
        }
        // POST api/<controller>
        public void Post(int userId, long bookId)
        {
            WaitingBooks wb = new WaitingBooks();

            long[] books = wb.GetBooksFromList(userId);
            wb.AddToList(userId, bookId, books);
        }
        // GET api/<controller>
        public List <Book> Get(int userId)
        {
            WaitingBooks wb = new WaitingBooks();
            Book         b  = new Book();

            return(b.getBooksArr(wb.GetBooksFromList(userId)));
            // return wb.GetBooksFromList(userId);
        }
        //libraryID, bookID
        // PUT api/<controller>/5
        public List <User> Put(int userID, long bookID, long isbn)
        {
            Library l = new Library();

            //פונקציה מביאה את כל הספרים מהספריה
            long[] arr = l.GetBooksFromLibrary(userID);
            // פונקציה מוסיפה ספר למערך ספרים בספרייה
            l.AddBook(bookID, arr, userID);

            WaitingBooks wb = new WaitingBooks();

            int[] waitingUsers = wb.GetWaitingUsers(bookID);
            User  u            = new User();

            return(u.GetUSersById(waitingUsers));
        }