code: func (c *client) RejoinReq(pl backend.RejoinReqPayload) (backend.RejoinAnsPayload, error) {
  	var ans backend.RejoinAnsPayload
  
  	b, err := json.Marshal(pl)
  	if err != nil {
  		return ans, errors.Wrap(err, "marshal request error")
  	}
  
  	resp, err := c.httpClient.Post(c.server, "application/json", bytes.NewReader(b))
  	if err != nil {
  		return ans, errors.Wrap(err, "http post error")
  	}
  	defer resp.Body.Close()
  
  	err = json.NewDecoder(resp.Body).Decode(&ans)
  	if err != nil {
  		return ans, errors.Wrap(err, "unmarshal response error")
  	}
  
  	if ans.Result.ResultCode != backend.Success {
  		return ans, fmt.Errorf("response error, code: %s, description: %s", ans.Result.ResultCode, ans.Result.Description)
  	}
  
  	return ans, nil
  }
docs: // RejoinReq issues a rejoin-request.