[Demonstration 1]

[Buggy Method]
void setTesting(boolean testing) {
    this.testing = testing;
}

[Buggy Hunk]
void setTesting(boolean testing) {

[Patch]
synchronized void setTesting(boolean testing) {

[Demonstration 2]

[Buggy Method]
public void handle(MMessage message, WNode node) {
    try {
        inputbytecount += message.getByteCount();
        log.info(this.toString() + " " + message);
        //
        WData nodeinfo = message.get("nodeinfo");
        if (nodeinfo != null) {
            handleNodeInfo(nodeinfo);
        }
        //
        MessageID responseto = message.getResponseTo();
        MessageResponseListener responselistener = getResponseListener(responseto);
        if (responselistener != null) {
            responselistener.messageReceived(message);
            removeResponseListener(responseto);
        } else {
            MNodeID to = message.getTo("to");
            if (to == null || to.equals(getID())) {
                handleMyMessage(message, node);
            } else {
                redirectMessageTo(message, node, to);
            }
        }
    } catch (Exception e) {
        log.error(e);
        server.getNodeStatus(node).warning();
    }
}

[Buggy Hunk]
MNodeID to = message.getTo("to");

[Patch]
MNodeID to = message.getTo();

[Demonstration 3]

[Buggy Method]
public void sendMail(String to, String subject, String body) {
    SimpleMailMessage message = new SimpleMailMessage();
    message.setTo(to);
    message.setSubject(subject);
    message.setText(body);
    javaMailSender.send(message);
}

[Buggy Hunk]
public void sendMail(String to, String subject, String body) {

[Patch]
public void sendMail(String to, String subject, String body) throws MailException {