/** {@inheritDoc} */
 public function export()
 {
     $parentExport = parent::export();
     $export = [];
     foreach ($parentExport as $property => $value) {
         if (!isset($this->changedProperties[$property]) || true !== $this->changedProperties[$property]) {
             continue;
         }
         $export[$property] = $value;
     }
     return $export;
 }