public ModelToModel GetAll()
        {
            ModelToModel mm;

            mm = new ModelToModel();
            mm.books = new List<Book>();
            using (BookMarketDbContext db = new BookMarketDbContext())
            {
                foreach (Book entry in db.GetAllBooks())
                {
                    mm.books.Add(entry);
                }
            }
            return mm;
        }