code: func (p *WebPage) Content() (string, error) {
  	var resp struct {
  		Value string `json:"value"`
  	}
  	if err := p.ref.process.doJSON("POST", "/webpage/Content", map[string]interface{}{"ref": p.ref.id}, &resp); err != nil {
  		return "", err
  	}
  	return resp.Value, nil
  }
docs: // Content returns content of the webpage enclosed in an HTML/XML element.