[Demonstration 1]

[Buggy Method]
@Override
public boolean containsKey(K key) {
    return this.value.containsKey(key);
}

[Buggy Hunk]
public boolean containsKey(K key)

[Patch]
public boolean containsKey(final K key)

[Demonstration 2]

[Buggy Method]
public IUser<Long> getUser(String login, String pwd) {
    UserDAO uDao = new UserDAO();
    IUser<Long> user = uDao.findByLogin(login);
    if (user != null) {
        String pwdHash = StringUtil.encode(pwd);
        if (user.getPwdHash() != null && user.getPwdHash().equals(pwdHash)) {
            user.setAuthorized(true);
            if (user.isSuperUser()) {
                user = new SuperUser(user.getLogin());
            }
        } else {
            Server.logger.errorLogEntry("password has not been encoded");
            user.setAuthorized(false);
        }
        if (user.isAuthorized()) {
            IEmployeeDAO eDao = null;
            try {
                Class<?> clazz = Class.forName(EnvConst.STAFF_DAO_CLASS);
                Class[] args = new Class[] { _Session.class };
                Constructor<?> contructor = clazz.getConstructor(args);
                _Session ses = new _Session(env, new AnonymousUser());
                eDao = (IEmployeeDAO) contructor.newInstance(new Object[] { ses });
            } catch (InstantiationException | IllegalAccessException | IllegalArgumentException | InvocationTargetException | ClassNotFoundException | NoSuchMethodException | SecurityException e) {
                Server.logger.errorLogEntry(e);
            }
            if (eDao != null) {
                IEmployee emp = eDao.getEmployee(user.getId());
                if (emp != null) {
                    user.setUserName(emp.getName());
                    user.setRoles(emp.getAllRoles());
                } else {
                    user.setUserName(user.getLogin());
                    user.setRoles(new ArrayList<String>());
                }
            }
        }
    } else {
        Server.logger.warningLogEntry("\"" + login + "\" user not found");
    }
    return user;
}

[Buggy Hunk]
if (eDao != null) {

[Patch]
if (user.getId() != SuperUser.ID && eDao != null) {

[Demonstration 3]

[Buggy Method]
public Page<K> next(K key) throws Exception {
    K next = st.floor(key);
    return serializer.readPage(st.get(next));
}

[Buggy Hunk]
return serializer.readPage(st.get(next));

[Patch]
return serializer.read(st.get(next));