[Demonstration 1]

[Buggy Method]
public String createToken(String userId) {
    logger.debug("Enter. userId: {}.", userId);
    String key = USER_DEVICE_TOKEN_PREFIX + userId;
    String token = (String) redisTemplate.opsForValue().get(key);
    if (StringUtils.isBlank(token)) {
        token = RandomStringUtils.randomAlphanumeric(TOKEN_LENGTH);
        redisTemplate.opsForValue().set(key, token, EXPIRE_TIME, TimeUnit.SECONDS);
    }
    logger.debug("Exit. token: {}.", token);
    return token;
}

[Buggy Hunk]
redisTemplate.opsForValue().set(key, token, EXPIRE_TIME, TimeUnit.SECONDS);

[Patch]
redisTemplate.opsForValue().set(key, token, EXPIRE_TIME, TimeUnit.MINUTES);

[Demonstration 2]

[Buggy Method]
@Override
public List<Class<? extends AsyncEventListener>> getListenerClasses(Class<? extends AsyncEvent> eventClass) {
    TypeLiteral<Set<Listener>> listenersKey = new TypeLiteral<Set<Listener>>() {
    };
    Set<Listener> listeners = injector.getInstance(Key.get(listenersKey));
    List<Class<? extends AsyncEventListener>> listenerClasses = Lists.newArrayList();
    for (Listener listener : listeners) {
        Class<? extends AsyncEvent> genericEventClass = getListenerEventClass(listener);
        if (genericEventClass.equals(eventClass)) {
            if (!listenerClasses.contains(listener.getListenerClass())) {
                listenerClasses.add(listener.getListenerClass());
            }
        }
    }
    return listenerClasses;
}

[Buggy Hunk]
if (genericEventClass.equals(eventClass)){

[Patch]
if (genericEventClass != null && genericEventClass.equals(eventClass)){

[Demonstration 3]

[Buggy Method]
@Override
public long queryDiskUsage() throws SQLException {
    long result = 0;
    ResultSet rs = null;
    try {
        rs = _queryDiskUsageStatement.executeQuery();
        if (rs.next()) {
            result = rs.getLong(1);
        }
    } finally {
        if (rs != null && !rs.isClosed()) {
            rs.close();
        }
    }
    return result;
}

[Buggy Hunk]
public long queryDiskUsage() throws SQLException{

[Patch]
public synchronized long queryDiskUsage() throws SQLException{