code: public function getSlice($offset, $length)
      {
          $select = clone $this->select;
          $sql = $select
              ->offset($offset)
              ->limit($length)
              ->getStatement();
          $sth = $this->pdo->prepare($sql);
          $sth->execute($this->select->getBindValues());
          $result = $sth->fetchAll(\PDO::FETCH_ASSOC);
  
          return $result;
      }
docs: {@inheritdoc}