Protected method in controller

In CI3 I was able to set private o protected method in controller, for example:

Code:

    private function _human_filesize($bytes, $decimals = 2)
    {
        $factor = floor((strlen($bytes) - 1) / 3);
        if ($factor > 0) $sz = 'KMGT';
        return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . @$sz[$factor - 1] . 'B';
    }

then I could call the private function within the same controller with:

Code:

    $this->_human_filesize($size);

Can we do the same in CI4? ...Sorry I'm a bit lost about this point reading the online guide

In CI3 I was able to set private o protected method in controller, for example:

Code:

    private function _human_filesize($bytes, $decimals = 2)
    {
        $factor = floor((strlen($bytes) - 1) / 3);
        if ($factor > 0) $sz = 'KMGT';
        return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . @$sz[$factor - 1] . 'B';
    }

then I could call the private function within the same controller with:

Code:

    $this->_human_filesize($size);

Can we do the same in CI4? ...Sorry I'm a bit lost about this point reading the online guide

Private functions are part of the PHP language so they would work in CI4 the same way as in CI3.