constraints.fill = GridBagConstraints.BOTH;
constraints.gridwidth = 1;
constraints.gridx++;
constraints.weightx = 1;
constraints.weighty = 1;
contentPane = new JCloseableTabbedPane();
contentPane.setPreferredSize(new Dimension(900, 600));
contentPane.addChangeListener(new ChangeListener() {
public void stateChanged(@SuppressWarnings("unused") ChangeEvent e) {
displayErrorDescription();