/**
  *
  */
 public function removeCaptionFile($pn_caption_id)
 {
     if (!$this->getPrimaryKey()) {
         return null;
     }
     $t_caption = new ca_object_representation_captions($pn_caption_id);
     if ($t_caption->get('representation_id') == $this->getPrimaryKey()) {
         $t_caption->setMode(ACCESS_WRITE);
         $t_caption->delete();
         if ($t_caption->numErrors()) {
             $this->errors = array_merge($this->errors, $t_caption->errors);
             return false;
         }
     } else {
         $this->postError(2720, _t('Caption file is not part of this representation'), 'ca_object_representations->removeCaptionFile()');
         return false;
     }
     return true;
 }