code: private function saveBaseColumns(IItem $item, $timestamp)
      {
          $isNew = false;
          $item->set('tstamp', $timestamp);
          if (!$item->get('id')) {
              $isNew = true;
              $this->createNewItem($item);
          }
  
          // Update system columns.
          if (null !== $item->get('pid')) {
              $this->saveSimpleColumn('pid', [$item->get('id')], $item->get('pid'));
          }
          if (null !== $item->get('sorting')) {
              $this->saveSimpleColumn('sorting', [$item->get('id')], $item->get('sorting'));
          }
          $this->saveSimpleColumn('tstamp', [$item->get('id')], $item->get('tstamp'));
  
          return $isNew;
      }
docs: Save the base columns of an item and return true if it is a new item.
  
  @param IItem $item      The item to save.
  @param int   $timestamp The timestamp to use.
  
  @return bool