code: func (p *WebPage) ScrollPosition() (Position, error) {
  	var resp struct {
  		Top  int `json:"top"`
  		Left int `json:"left"`
  	}
  	if err := p.ref.process.doJSON("POST", "/webpage/ScrollPosition", map[string]interface{}{"ref": p.ref.id}, &resp); err != nil {
  		return Position{}, err
  	}
  	return Position{Top: resp.Top, Left: resp.Left}, nil
  }
docs: // ScrollPosition returns the current scroll position of the page.