Call BaseController custom function in view

How you can try to call the function if it has PRIVATE modificator?  Change private on public or protected!

It's a typographic error writing this post, the function is public:

PHP Code:

<?php

namespace App\Controllers;

use CodeIgniter\Controller;
use CodeIgniter\HTTP\RequestInterface;
use CodeIgniter\HTTP\ResponseInterface;
use Psr\Log\LoggerInterface;

class BaseController extends Controller
{

    protected $helpers = [];

    public function initController(RequestInterface $request, ResponseInterface $response, LoggerInterface $logger)
    {
        parent::initController($request, $response, $logger);

    }

    public function customFunction()
    {
          return 'Testing';
    }

} 


In view:

PHP Code:

<?php
<?= $this->extend('layout'); ?>

<?= $this->section('content') ?>

<div>
    /* I tried this but do not work */
    <?= $this->customFunction(); ?>
</div>

<?= $this->endSection(); ?>