public function onAfterWrite()
 {
     if (is_a($this->owner, 'Image')) {
         SectionIO::flushImage($this->owner->ID);
     } else {
         SectionIO::flushFile($this->owner->ID);
     }
 }
 public function onAfterPublish()
 {
     SectionIO::flushSiteTree($this->owner->ID);
 }