//
 //PUT: /Books/1
 public bool Put(int id, Book book)
 {
     book.id = id;
     if (book == null)
     {
         throw new ArgumentNullException("book");
     }
     int index = books.FindIndex(p => p.id == book.id);
     if (index == -1)
     {
         return false;
     }
     books.RemoveAt(index);
     books.Add(book);
     return true;
 }
 //
 //POST: /Books/
 public HttpResponseMessage PostBook(Book book)
 {
     books.Add(book);
     var response = Request.CreateResponse<Book>(HttpStatusCode.Created, book);
     return response;
 }