public function getStopWords($string, $language = 'english')
    {
        $words = $this->getWords($string);
        $filter = new StopWordsFilter($language);
        $stopWords = [];

        foreach ($words as $word) {
            if (!is_null($filter->filter($word))) {
                $stopWords[] = $word;
            }
        }

        return $stopWords;
    }