public static void main(String[] args) {
        BufferedReader rd = null;
        PipedInputStream pis = null;
        PipedOutputStream pos = null;
        ObjectInputStream ois = null;
        ObjectOutputStream oos = null;
        try {
            rd = new BufferedReader(new FileReader("countries.csv"));
            Labor_09.readFile(rd);
            pis = new PipedInputStream();
            pos = new PipedOutputStream(pis);
            oos = new ObjectOutputStream(pos);
            ois = new ObjectInputStream(pis);
            oos.writeObject(countries);
do->        countries_2 = (List<Country>) ois.readObject();
        } catch (FileNotFoundException ex) {
            System.err.println("Datei wurde nicht gefunden!");
        } catch (IOException ex) {
            System.err.println("Allgemeiner Fehler ist aufgetreten!");
        } finally {
            if (rd != null) {
                try {
                    rd.close();
                } catch (IOException ex) {
                }
            }
        }
    }