private function isComment($line)
    {
        // if it's an empty line you might as well skip it
        if (empty($line)) return true;

        $is_comment = false;

        foreach ($this->_comment_character_list as $comment_char) {
            $line = trim($line);
            if (strpos($line, $comment_char) !== false && strpos($line, $comment_char) <= 3) {
                $is_comment = true;
                break;
            }
        }

        return $is_comment;
    }