code: func postJSON(ctx context.Context, client httpClient, endpoint, token string, json []byte, intf interface{}, d debug) error {
  	reqBody := bytes.NewBuffer(json)
  	req, err := http.NewRequest("POST", endpoint, reqBody)
  	if err != nil {
  		return err
  	}
  	req.Header.Set("Content-Type", "application/json")
  	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", token))
  	return doPost(ctx, client, req, intf, d)
  }
docs: // post JSON.