public function getContentSummary(DBHTMLText $content)
    {
        switch ($this->owner->SummaryMode) {
            case self::SUMMARY_FIRST_SENTENCE:
                return $content->FirstSentence();
            case self::SUMMARY_FIRST_PARAGRAPH:
                return $content->FirstParagraph();
            default:
                return StringTools::singleton()->getContentSummary($content);
        }
    }