public List <Book> GetReadersBooks(int readerId)
        {
            var readersBooks = database.books.Where((book) => book.IsTaken == true && book.UserId == readerId);

            return(DBToLibrary.BookListToLibrary(readersBooks.ToList <DatabaseWithEntity.books>()));
        }
        public List <Book> Find(string search)
        {
            var booksFound = database.books.Where((book) => book.Name.Contains(search) || book.Author.Contains(search));

            return(DBToLibrary.BookListToLibrary(booksFound.ToList <DatabaseWithEntity.books>()));
        }
        public List <Book> GetAllBooks()
        {
            var booksFromDB = database.books;

            return(DBToLibrary.BookListToLibrary(booksFromDB.ToList <DatabaseWithEntity.books>()));
        }