code: public function getOwner()
      {
          if (!$this->isOwnable) {
              return;
          }
          $ownerObject = $this->getOwnerObject();
          if (is_object($ownerObject)) {
              return $ownerObject->primaryKey;
          }
  
          return $ownerObject;
      }
docs: Get owner.
  
  @return [[@doctodo return_type:getOwner]] [[@doctodo return_description:getOwner]]