public function cropAtSentence($string, $maximumCharacters, $suffix = '')
    {
        $string = (string)$string;

        if (UnicodeFunctions::strlen($string) > $maximumCharacters) {
            $iterator = new TextIterator($string, TextIterator::SENTENCE);
            $string = UnicodeFunctions::substr($string, 0, $iterator->preceding($maximumCharacters));
            $string .= $suffix;
        }

        return $string;
    }