[Demonstration 1]

[Buggy Method]
public String averageAnswerRateOfCardsBeforeTestAsString() {
    DecimalFormat df = new DecimalFormat("#.0000");
    return df.format(answerDatasByStudyItemsBeforeTest.getAverageAnswerRateOfStudyItems());
}

[Buggy Hunk]
return df.format(answerDatasByStudyItemsBeforeTest.getAverageAnswerRateOfStudyItems());

[Patch]
return df.format(relevantAnswerDatasByStudyItemsBeforeTest.getAverageAnswerRateOfStudyItems());

[Demonstration 2]

[Buggy Method]
public static Result service(String ownerName, String projectName, String service, boolean isAdvertise) throws IOException, UnsupportedOperationException, ServletException {
    if (!isSupportedService(service)) {
        return forbidden(String.format("Unsupported service: '%s'", service));
    }
    Project project = Project.findByOwnerAndProjectName(ownerName, projectName);
    if (project == null) {
        return notFound();
    }
    models.User user = UserApp.currentUser();
    if (!isAllowed(project, service)) {
        if (user.isAnonymous()) {
            return BasicAuthAction.unauthorized(response());
        } else {
            // If you want the Git client showing your custom message to
            // the user, the Content-Type should be exact "text/plain"
            // without any parameter. For more details, see the code at
            // https://github.com/git/git/commit/426e70d4a11ce3b4f70636d57c6a0ab16ae08a00#diff-eea0ad565ec5903a11b6023755d491cfR154
            response().setHeader("Content-Type", "text/plain");
            return forbidden(String.format("'%s' has no permission to '%s/%s'.", user.name, ownerName, projectName));
        }
    }
    if (isAdvertise) {
        return ok(RepositoryService.gitAdvertise(project, service, response()));
    } else {
        if (request().body().isMaxSizeExceeded()) {
            return status(REQUEST_ENTITY_TOO_LARGE);
        } else {
            user.visits(project);
            return ok(RepositoryService.gitRpc(project, service, request(), response()));
        }
    }
}

[Buggy Hunk]
user.name, ownerName, projectName));

[Patch]
user.loginId, ownerName, projectName));

[Demonstration 3]

[Buggy Method]
private long parseDateOrNums(String stringDate) {
    if (stringDate.toLowerCase().contains("m") && stringDate.toLowerCase().contains("d")) {
        return parseNumsAndLatters(stringDate);
    } else {
        SimpleDateFormat sdf = new SimpleDateFormat(this.config.getDateFormat());
        GregorianCalendar cal = new GregorianCalendar();
        try {
            cal.setTime(sdf.parse(stringDate));
        } catch (Exception e) {
            e.printStackTrace();
        }
        return cal.getTimeInMillis();
    }
}

[Buggy Hunk]
if (stringDate.toLowerCase().contains("m") && stringDate.toLowerCase().contains("d")){

[Patch]
if (stringDate.toLowerCase().contains("m") || stringDate.toLowerCase().contains("d")){