[Demonstration 1]

[Buggy Method]
public UserClient create(UserClient userClient) throws BadRequestException {
    log.info("UserClientServices create: {}", userClient.getName());
    userClient.setDateCreated(new Date().getTime());
    userClient.setActive(true);
    List<Subsidiary> subsidiarieList = userClient.getSubsidiaries();
    userClient.setSubsidiaries(null);
    if (subsidiarieList == null) {
        throw new BadRequestException("Debe tener una sucursal por lo menos");
    }
    UserClient saved = userClientRepository.save(userClient);
    subsidiarieList.forEach(subsidiary -> {
        subsidiary.setUserClient(saved);
        subsidiaryRepository.save(subsidiary);
        subsidiary.setUserClient(null);
    });
    log.info("UserClientServices created: {}", userClient.getId());
    saved.setSubsidiaries(subsidiarieList);
    return saved;
}

[Buggy Hunk]
if(subsidiarieList == null){

[Patch]
if(subsidiarieList == null || subsidiarieList.isEmpty()){

[Demonstration 2]

[Buggy Method]
@Override
public String toString() {
    String s = "\n{" + "\n\tUsername: " + getUsername() + "\n\tAccount Number: " + getAccountNumber() + "\n\tAccount Balance: " + getBalance() + "\n\tAccount Currency Type: " + stringCurrencyType() + "\n}\n";
    return s;
}

[Buggy Hunk]
+ "\n\tAccount Balance: " + getBalance()

[Patch]
+ "\n\tAccount Balance: " + df.format(getBalance())

[Demonstration 3]

[Buggy Method]
public void save() {
    YamlConfiguration yml = new YamlConfiguration();
    rewardsWaiting.forEach((uuid, amount) -> {
        yml.set(uuid.toString() + ".amount", amount);
        yml.set(uuid.toString() + ".name", names.get(uuid));
    });
    try {
        yml.save(file);
    } catch (IOException e) {
        ServerSaturday.instance().getLogger().warning("Could not save rewards_waiting.yml");
    }
}

[Buggy Hunk]
yml.set(uuid.toString() + ".name", names.get(uuid));

[Patch]
yml.set(uuid.toString() + ".name", ServerSaturday.instance().getUUIDCache().getNameOf(uuid));