private static function isAbreviation($fragment)
    {
        $words = mb_split('\s+', Multibyte::trim($fragment));

        $word_count = count($words);

        $last_word = Multibyte::trim($words[$word_count - 1]);
        $last_is_capital = preg_match('#^\p{Lu}#u', $last_word);
        $last_is_abbreviation = mb_substr(Multibyte::trim($fragment), -1) === '.';

        return $last_is_capital > 0
            && $last_is_abbreviation > 0
            && mb_strlen($last_word) <= 3;
    }