code: public function resetFallback($strField)
      {
          // @codingStandardsIgnoreStart
          @trigger_error(__CLASS__ . '::' . __METHOD__ . ' is deprecated - handle resetting manually', E_USER_DEPRECATED);
          // @codingStandardsIgnoreEnd
  
          $metaModel = $this->getMetaModel();
          $attribute = $metaModel->getAttribute($strField);
          $ids       = $metaModel->getIdsFromFilter(null);
  
          if ($attribute instanceof IComplex) {
              $attribute->unsetDataFor($ids);
          }
          if ($attribute instanceof ITranslated) {
              $attribute->unsetValueFor($ids, $this->getCurrentLanguage());
          }
          if ($attribute instanceof IAttribute) {
              $data = array();
              foreach ($ids as $id) {
                  $data[$id] = null;
              }
              $attribute->setDataFor($data);
          }
  
          throw new \RuntimeException('Unknown attribute or type ' . $strField);
      }
docs: Reset the fallback field.
  
  This clears the given property in all items in the data provider to an empty value.
  
  @param string $strField The field to reset.
  
  @return void
  
  @throws \RuntimeException For invalid ids.