code: func (p *WebPage) PaperSize() (PaperSize, error) {
  	var resp struct {
  		Value paperSizeJSON `json:"value"`
  	}
  	if err := p.ref.process.doJSON("POST", "/webpage/PaperSize", map[string]interface{}{"ref": p.ref.id}, &resp); err != nil {
  		return PaperSize{}, err
  	}
  	return decodePaperSizeJSON(resp.Value), nil
  }
docs: // PaperSize returns the size of the web page when rendered as a PDF.