public function whenBookSaleCompleted(BookSaleCompleted $event)
{
$book = $this->books->find((string) $event->bookId());
$book = new BookTransaction($book->bookId(), $book->title(), $book->sellersId(), $book->sellersName(), $buyer->memberId(), $buyer->fullName(), $book->price(), true, false);
$this->books->save($book);
}
public function whenBookSaleCompleted(BookSaleCompleted $event)
{
$this->books->remove($event->bookId());
}