static public void UpdateAuthor(Author editedAuthor)
        {
            Author authObj = AuthorManager.GetAuthor(editedAuthor.Aid);

            authObj.Aid       = editedAuthor.Aid;
            authObj.FirstName = editedAuthor.FirstName;
            authObj.LastName  = editedAuthor.LastName;
            authObj.BirthYear = editedAuthor.BirthYear;
            _EAuthorRepo.Update(MapAuthor(authObj).authorobj);
        }
        // Constructor - sets all info about object and list of the books author has written
        public AuthorManager(int id)
        {
            this.id = id;

            Author authobj        = AuthorManager.GetAuthor(id);    // gets the author by id
            var    authorBookList = BookManager.GetBooksByAid(id);  // gets the books the author has written

            Aid       = authobj.Aid;
            FirstName = authobj.FirstName;
            LastName  = authobj.LastName;
            BirthYear = authobj.BirthYear;

            AuthBooks = authorBookList;
        }
        // constructor for bookmanager. sets book info and a list of the books autor(s)
        public BookManager(string id)
        {
            this.id = id;
            Book bookobj        = BookManager.GetBooks(id);
            var  bookAuthorList = AuthorManager.GetAuthorByIsbn(id);    // gets book by isbn
            var  bookAuthList   = AuthorManager.GetAuthorByIsbn(id);    // gets the author(s) who wrote the book

            ISBN            = bookobj.ISBN;
            Title           = bookobj.Title;
            PublicationYear = bookobj.PublicationYear;
            Publicationinfo = bookobj.Publicationinfo;
            Pages           = bookobj.Pages;
            BookAuthor      = bookAuthorList;
            BookAuth        = bookAuthList;
        }