private function CheckData($key)
    {
        if (!is_array($this->row))
            throw new \BadMethodCallException('MysqliReader has no data. Call Read method or check query.');
          
        if (!array_key_exists($key, $this->row))
            throw new \InvalidArgumentException('Mysqli Reader has no index ' . $key);
    
          if ($this->IsClosed())
            throw new \BadMethodCallException('MysqliReader is closed.');
          
    }