public Book ToDomainModel(BookDb book) { return(new Book { Id = book.Id, Title = book.Title, PageCount = book.PageCount, Publisher = book.Publisher, Year = book.Year, Isbn = book.Isbn, Image = book.Image, Token = book.Token, CreateDate = book.CreateDate, EditDate = book.EditDate, Authors = _authorMapper .ToDomainModel(book.Authors) ?.ToList() }); }