code: func (c *Client) UploadRaw(r io.Reader, size int64, toEncrypt bool) (string, error) {
  	if size <= 0 {
  		return "", errors.New("data size must be greater than zero")
  	}
  	addr := ""
  	if toEncrypt {
  		addr = "encrypt"
  	}
  	req, err := http.NewRequest("POST", c.Gateway+"/bzz-raw:/"+addr, r)
  	if err != nil {
  		return "", err
  	}
  	req.ContentLength = size
  	res, err := http.DefaultClient.Do(req)
  	if err != nil {
  		return "", err
  	}
  	defer res.Body.Close()
  	if res.StatusCode != http.StatusOK {
  		return "", fmt.Errorf("unexpected HTTP status: %s", res.Status)
  	}
  	data, err := ioutil.ReadAll(res.Body)
  	if err != nil {
  		return "", err
  	}
  	return string(data), nil
  }
docs: // UploadRaw uploads raw data to swarm and returns the resulting hash. If toEncrypt is true it
  // uploads encrypted data