this.add(panDisplay, BorderLayout.CENTER);
add(panDisplay, BorderLayout.CENTER);
    public ClientGUI(Client client) {        super(new BorderLayout());        this.client = client;        loadSoundClip();        panMain.setLayout(cardsMain);        panSecondary.setLayout(cardsSecondary);        JPanel panDisplay = new JPanel(new BorderLayout());        panDisplay.add(panMain, BorderLayout.CENTER);        panDisplay.add(panSecondary, BorderLayout.SOUTH);        this.add(panDisplay, BorderLayout.CENTER);    }