[Demonstration 1]

[Buggy Method]
@Override
public void show(FieldsResponse fieldsResponse) {
    clear();
    Map<String, Object> fields = fieldsResponse.getFields();
    if (fields == null || fields.isEmpty()) {
        setText(0, 0, "No data.");
        return;
    }
    int row = 0;
    for (Map.Entry<String, Object> entry : fields.entrySet()) {
        setText(row, 0, entry.getKey());
        // To clear colspans.
        getFlexCellFormatter().setColSpan(row, 0, 0);
        if (entry.getValue() instanceof String) {
            TextBox textBox = new TextBox();
            textBox.setValue((String) entry.getValue());
            editBoxes.put(entry.getKey(), textBox);
            setWidget(row, 1, textBox);
        } else if (entry.getValue() instanceof Integer) {
            IntegerBox intBox = new IntegerBox();
            intBox.setValue((Integer) entry.getValue());
            editBoxes.put(entry.getKey(), intBox);
            setWidget(row, 1, intBox);
        } else if (entry.getValue() instanceof NullInteger) {
            NullInteger niValue = (NullInteger) entry.getValue();
            IntegerBox intBox = new IntegerBox();
            intBox.setValue(niValue.getValue());
            editBoxes.put(entry.getKey(), intBox);
            setWidget(row, 1, intBox);
        } else if (entry.getValue() instanceof Boolean) {
            CheckBox checkBox = new CheckBox();
            checkBox.setValue((Boolean) entry.getValue());
            editBoxes.put(entry.getKey(), checkBox);
            setWidget(row, 1, checkBox);
        } else if (entry.getValue() instanceof NullBool) {
            NullBool nbValue = (NullBool) entry.getValue();
            NullBoolBox box = new NullBoolBox();
            box.setValue(nbValue.getValue());
            editBoxes.put(entry.getKey(), box);
            setWidget(row, 1, box);
        } else {
            setText(row, 1, "-- \" --");
        }
        row++;
    }
    addButtons(row);
}

[Buggy Hunk]
getFlexCellFormatter().setColSpan(row, 0, 0); // To clear colspans.

[Patch]
defaultFormattingFor(row, 0);

[Demonstration 2]

[Buggy Method]
@Override
public void focus(FieldEvents.FocusEvent event) {
    if (form.isShown())
        form.toggle();
}

[Buggy Hunk]
if (form.isShown()) form.toggle();

[Patch]
form.toggleIf(false);

[Demonstration 3]

[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));