public bool Insert(Book book)
        {
            try
            {
                this.context.Books.InsertOnSubmit(book);
                this.context.SubmitChanges();
            }
            catch (SqlException e)
            {
                Console.WriteLine(e.Message);
                return false;
            }

            return true;
        }
 partial void UpdateBook(Book instance);
 partial void DeleteBook(Book instance);
 partial void InsertBook(Book instance);