protected static function intersect($string, $subString, $start)
    {
        $cut = str_split(substr($string, $start, strlen($subString)));
        $comp = str_split($subString);
        foreach ($cut as $i => $c) {
            if ($comp[$i] === $c) {
                $intersect[] = $c;
            } else {
                break; // Stop loop since intersection ends.
            }
        }
        if (!empty($intersect)) {
            return implode('', $intersect);
        }

        return '';
    }