public ActionResult <BookDto> CreateBookForAuthor(Guid authorId, BookForCreationDto bookForCreationDto) { if (!_bookLibraryRepository.AuthorExists(authorId)) { return(NotFound()); } var bookEntity = _mapper.Map <Book>(bookForCreationDto); _bookLibraryRepository.AddBook(authorId, bookEntity); _bookLibraryRepository.Save(); var bookToReturn = _mapper.Map <BookDto>(bookEntity); return(CreatedAtRoute("GetBookForAuthor", new { authorId, bookId = bookToReturn.Id }, bookToReturn)); }