public function getWords($string, $minLength = null)
    {
        $tokenizer = new Whitespace();
        $words = $tokenizer->tokenize($string);

        if (!is_null($minLength)) {
            foreach ($words as $key => $word) {
                if (strlen($word) <= $minLength) {
                    unset($words[$key]);
                }
            }
        }

        return array_values($words);
    }