package org.codehaus.xfire.castor;public class BookService{    private Book onlyBook;    public BookService()    {        onlyBook = new Book();        onlyBook.setAuthor("Steve Ballmer");        onlyBook.setTitle("How to Yell Real Loud and Look Like You Might Have a Heart Attack");        onlyBook.setIsbn("012924828");    }    public String addBook(Book book)    {        return onlyBook.getIsbn();    }    public Book findBook(String isbn)    {        return onlyBook;    }}