[Demonstration 1]

[Buggy Method]
@RequestMapping(value = { "/argos/daily" })
@ResponseBody
private String getArgosDailyData(@RequestParam short domain_id, @RequestParam long from_time, @RequestParam long to_time, @RequestParam(required = false, defaultValue = "jennifer") String customer_id) throws MalformedURLException {
    URL u = new URL(ARGOS_API_URL + "?func_name=getMeasureDataSummaryListForJennifer&domain_id=" + domain_id + "&customer_id=" + customer_id + "&from_time=" + from_time + "&to_time=" + to_time);
    return getArgosContents(u);
}

[Buggy Hunk]
return getArgosContents(u);

[Patch]
return getArgosContents(u, false);

[Demonstration 2]

[Buggy Method]
public UserLocal getUser(String id) {
    UserLocal u = userMap.get(id);
    if (u == null) {
        u = new Guest(id);
        userMap.put(id, u);
    }
    return u;
}

[Buggy Hunk]
UserLocal u = userMap.get(id);

[Patch]
User u = userMap.get(id);

[Demonstration 3]

[Buggy Method]
public Notification toNotification() {
    ObjectMapper mapper = new ObjectMapper();
    try {
        return mapper.convertValue(getObj(), (Class<? extends Notification>) Thread.currentThread().getContextClassLoader().loadClass(getType()));
    } catch (Exception e) {
        logger.error("Problem to load class {}", getType());
        return null;
    }
}

[Buggy Hunk]
logger.error("Problem to load class {}", getType());

[Patch]
logger.error("Problem to load class {}", getType(), e);