public List<Map<String, ?>> getBooksWithMember(Long memberId) {
Preconditions.checkNotNull(memberId);
booksWithMember = libraryFinder.findAllBooksWithMember(memberId);
return booksWithMember;
}
public List<Map<String, ?>> getAllBooks() {
allBooks = libraryFinder.findAllBooks();
return allBooks;
}