public IList<Book> GetAllBooksByTagName(string tagName)
        {
            List<Book> books;
            BookTag tag;

            books = new List<Book>();
            using (BookMarketDbContext db = new BookMarketDbContext())
            {
                foreach (Book entry in db.GetAllBooksByTagName(tagName))
                    books.Add(entry);
            }

            return books;
        }