"Cannot access ..." do paczki w Optional

@Entity(name = "book_data")
class BookData {

    @Id
    @GeneratedValue(generator = "book_data_id", strategy = GenerationType.SEQUENCE)
    @SequenceGenerator(name = "book_data_id", sequenceName = "book_data_id", allocationSize = 1)
    private Long id;

    @Getter
    @Column(unique = true, nullable = false, name = "uuid", length = 36)
    private UUID uuid;

    private BookData() {}

    BookData(UUID uuid) {
        this.uuid = uuid;
    }
}

interface Book extends JpaRepository<BookData, Long> {

    Optional<BookData> findByUUID(UUID uuid);

    default void saveEvents(UUID uuid) {
        final Optional<BookData> bookById = findByUUID(uuid) // tutaj juz jest blad 
                .orElse(new BookData(aggregateId)); // tutaj rowniez
    }
}