@Override
public void actionPerformed(ActionEvent e) {
try {
if (netScan != null) return;
scan.setEnabled(false);
netScan = new NetworkScan(new Subnet(addr.getText(), sub.getText()), new ChangeListener() {
@Override
@SuppressWarnings("unchecked")
public void stateChanged(ChangeEvent e) {
InetAddress address = ((Tuple<InetAddress, PingMethod>)e.getSource()).getFirst();
JCheckBox c = new JCheckBox(address.getHostAddress(), true);