code: public function save($timestamp = null)
      {
          if (null === $timestamp) {
              // @codingStandardsIgnoreStart
              @\trigger_error(
                  'Not passing a timestamp has been deprecated and will cause an error in MetaModels 3',
                  E_USER_DEPRECATED
              );
              // @codingStandardsIgnoreEnd
          }
  
          $objMetaModel = $this->getMetaModel();
          $objMetaModel->saveItem($this, $timestamp);
      }
docs: Save the current data for every attribute to the data sink.
  
  @param int|null $timestamp Optional the timestamp.
  
  @return void