code: public function countById($id, $siteId)
      {
          $qa = $this->createAggregationQueryBuilderWithSiteId($siteId);
          $qa->match(
              array(
                  'nodeId' => $id,
                  'deleted'  => false,
              )
          );
  
          return $this->countDocumentAggregateQuery($qa);
      }
docs: @param string $parentId
  @param string $siteId
  
  @return int