[Demonstration 1]

[Buggy Method]
public void delete(String id, Handler<AsyncResult<Boolean>> resultHandler) {
    redisClient.del(sessionKeyBase + id, res -> {
        if (res.succeeded()) {
            resultHandler.handle(Future.succeededFuture(Boolean.valueOf(res.result() != null)));
        } else {
            resultHandler.handle(Future.failedFuture(res.cause()));
        }
    });
}

[Buggy Hunk]
resultHandler.handle(Future.succeededFuture(Boolean.valueOf(res.result() != null)));

[Patch]
resultHandler.handle(Future.succeededFuture(res.result() == 1L));

[Demonstration 2]

[Buggy Method]
@OnClick(R.id.payNowButton)
public void payNowClick() {
    if (cartProductsList.size() > 0) {
        MakeOrder order = new MakeOrder();
        Gson gson = new Gson();
        order.setCartPartDetailArrayList(cartProductsList);
        order.setTotalCharges("" + setTotalAmountTextView());
        String orderStr = gson.toJson(order);
        Intent intent = new Intent(ctx, ShippingAddressActivity.class);
        intent.putExtra("isComingFromSideMenu", false);
        intent.putExtra("order", orderStr);
        ctx.startActivityForResult(intent, AppCommon.SHIPPING_ADDRESS_REQUEST_CODE);
    } else {
        AppCommon.getInstance(getContext()).showDialog(ctx, "There is no product in cart.");
    }
}

[Buggy Hunk]
order.setTotalCharges("" + setTotalAmountTextView());

[Patch]
order.setTotalCharges("" + String.format("%.2f", setTotalAmountTextView()));

[Demonstration 3]

[Buggy Method]
public void startWithoutDelay(String filepath, CarActionsFilter... filter) {
    Set<CarActionsFilter> filters = new HashSet<>(Arrays.asList(filter));
    CarAction.addCreatedListener(this::newAction, filters);
    reader = new ReadFromOpenXCFile(filepath);
    reader.startReading();
}

[Buggy Hunk]
CarAction.addCreatedListener(this::newAction, filters);

[Patch]
CarAction.addCreatedListener(this, filters);