protected function add_answer_feedback_declaration(ImsQtiWriter $item, $question)
 {
     if ($this->has_answer_feedback($question)) {
         $result = $item->add_outcomeDeclaration_feedback();
         $result->add_defaultValue()->add_value('DEFAULT_FEEDBACK');
         return $result;
     } else {
         return null;
     }
 }
 protected function add_overall_feedback_declaration(ImsQtiWriter $item, $question)
 {
     $identifier = self::OVERALL_FEEDBACK;
     $result = $item->add_outcomeDeclaration_feedback($identifier);
     return $result;
 }