code: func (p *WebPage) SetPaperSize(size PaperSize) error {
  	req := map[string]interface{}{"ref": p.ref.id, "size": encodePaperSizeJSON(size)}
  	return p.ref.process.doJSON("POST", "/webpage/SetPaperSize", req, nil)
  }
docs: // SetPaperSize sets the size of the web page when rendered as a PDF.