code: func WorkareaGet(xu *xgbutil.XUtil) ([]Workarea, error) {
  	rects, err := xprop.PropValNums(xprop.GetProperty(xu, xu.RootWin(),
  		"_NET_WORKAREA"))
  	if err != nil {
  		return nil, err
  	}
  
  	workareas := make([]Workarea, len(rects)/4)
  	for i, _ := range workareas {
  		workareas[i] = Workarea{
  			X:      int(rects[i*4]),
  			Y:      int(rects[i*4+1]),
  			Width:  rects[i*4+2],
  			Height: rects[i*4+3],
  		}
  	}
  	return workareas, nil
  }
docs: // _NET_WORKAREA get