private function buildDescriptionView(PhabricatorCalendarEvent $event)
 {
     $viewer = $this->getViewer();
     $properties = id(new PHUIPropertyListView())->setUser($viewer);
     if (strlen($event->getDescription())) {
         $description = new PHUIRemarkupView($viewer, $event->getDescription());
         $properties->addTextContent($description);
         return $properties;
     }
     return null;
 }