def sync response_id = 0
      req = self.class.get '/sync/maindata', format: :json,
                           query: { rid: response_id }
      res = req.parsed_response

      if req.success?
        return res
      end
    end
def sync response_id = 0
      req = self.class.get '/sync/maindata', format: :json,
                           query: { rid: response_id }
      res = req.parsed_response

      if req.success?
        return res
      end
    end
Requests partial data from the client.

 @param response_id [Integer] Response ID. Used to keep track of what has
   already been sent by qBittorrent.

 @return [Hash, nil] parsed json data on success, nil otherwise

 @note Read more about `response_id` at https://github.com/qbittorrent/qBittorrent/wiki/WebUI-API-Documentation#get-partial-data