//problem 7
        public static string GetBooksReleasedBefore(BookShopContext context, string date) {
            StringBuilder output = new StringBuilder();
            //Return the title, edition type and price of all books that are released before a given date. The date will be a string in format dd-MM-yyyy.
          //  DateTime customDate = new DateTime();
           // customDate = customDate.AddYears(int.Parse(date.Split('-')[2]));
         //   customDate = customDate.AddMonths(int.Parse(date.Split('-')[1]));
          //  customDate = customDate.AddDays(int.Parse(date.Split('-')[0]));

            string[] bookTitles = context
                .Books

                .Where(book => book.ReleaseDate < DateTime.Parse(date))
                .OrderByDescending(book => book.ReleaseDate)
                 .Select(book => $"{book.Title} - {book.EditionType} - ${book.Price:f2}")

                .ToArray();



            foreach (string title in bookTitles)
            {
                output.AppendLine(title);
            }
            return output.ToString().TrimEnd();


        }