public function humanFileSize($bytes, $decimals = 2)
    {
        /** @var string $sizeLetters Size shortcuts */
        $sizeLetters = 'BKBMBGBTBPB';
        $factor = (int)(floor((strlen($bytes) - 1) / 3));
        $sizeLetter = ($factor <= 0) ? substr($sizeLetters, 0, 1) : substr($sizeLetters, $factor * 2 - 1, 2);
        return sprintf("%.{$decimals}f", $bytes / pow(1024, $factor)) . $sizeLetter;
    }