public static void fillWithExampleData(TFacade ap) {
        String t1[] = { "1", "Author1", "Title1", "ISBN1", "Publisher1" };
        String t2[] = { "1", "Author2", "Title2", "ISBN2", "Publisher2" };
        String t3[] = { "1", "Author3", "Title3", "ISBN3", "Publisher3" };
        String t4[] = { "3", "Author1", "Title1", "ISBN1", "Publisher1",
            "Actor1" };
        String t5[] = { "3", "Author2", "Title2", "ISBN2", "Publisher2",
            "Actor2" };
        String t6[] = { "3", "Author4", "Title4", "ISBN4", "Publisher4",
            "Actor4" };
        ap.add_title_book(t1);
        ap.add_title_book(t2);
        ap.add_title_book(t2);
        ap.add_title_book(t3);
        ap.add_title_book(t4);
        ap.add_title_book(t5);
        ap.add_title_book(t5);
        ap.add_title_book(t6);
        String lan = ap.getmTitle_books().toString();
        System.out.println(lan);
        
        //second iteration testing starts here
        System.out.println("printing titles");
        String d1[] = { "0", "ISBN1" };
        String d2[] = { "0", "ISBN2" };
        String d3[] = { "0", "ISBN5" };
        String d4[] = { "2", "ISBN1", "Actor1" };
        String d5[] = { "2", "ISBN4", "Actor4" };
        String tr1[] = { "0", "1" };
        String tr2[] = { "0", "2" };
        String tr3[] = { "1", "3", "3" };
        String tr4[] = { "1", "2", "-1" };
        TTitle_book pom = ap.add_book(d1, tr1);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d2, tr1);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d2, tr1);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d2, tr2);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d3, tr2);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d4, tr3);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d4, tr3);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d4, tr4);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        pom = ap.add_book(d5, tr2);
        if (pom != null) {
            System.out.print(pom.getmBooks().toString());
        }
        System.out.println();
        
        
        //fourth iteration starts here
        ap.Print_title_books();
        ap.Print_books();
//        if(2==1+1) throw new RuntimeException("only up to here implementation is done");
        System.out.print("\nSearching of a title");
        System.out.print(ap.Search_title_book(t5).toString());
        System.out.print("\nSearching of an accessible book of a select title");
        System.out.print(ap.Search_accessible_book(d4, "2").toString());
        System.out.print("\nSearching for book. Found following books: ");
        System.out.print(ap.Search_title_books(new String[] { "2", "N4", "Actor4" }));
        System.out.println();
        
//      fifth iteration
        
        //add clients
        ap.clients.add(new Client("Client1"));
        ap.clients.add(new Client("Client2"));
        ap.clients.add(new Client("Client3"));
        ap.clients.add(new Client("Client4"));
        ap.clients.add(new Client("Client5"));
        ap.clients.add(new Client("Client6"));
        ap.clients.add(new Client("Client7"));
//        TBook_period period1 = new TBook_period();
//        period1.setPeriod(TFactory.mdays("-2")); 
//        ap.add_book(new String[]{ "0", "ISBN5" }, new String[]{ "1", "5", "-2" });//book was returned 2 days ago
//        ap.Search_book(data1, data2);
//        TBook recentlyAddedBook = ap.mTitle_books.get(ap.mTitle_books.size()-1);
        TBook recentlyAddedBook=ap.Search_book(d4, tr4);
        System.out.println("Borrowing some book, expecting it to be "+recentlyAddedBook);
        
        System.out.print(ap.borrow_book(new Client("Client1"), recentlyAddedBook));
    }