code: func WmIconGet(xu *xgbutil.XUtil, win xproto.Window) ([]WmIcon, error) {
  	icon, err := xprop.PropValNums(xprop.GetProperty(xu, win, "_NET_WM_ICON"))
  	if err != nil {
  		return nil, err
  	}
  
  	wmicons := make([]WmIcon, 0)
  	start := uint(0)
  	for int(start) < len(icon) {
  		w, h := icon[start], icon[start+1]
  		upto := w * h
  
  		wmicon := WmIcon{
  			Width:  w,
  			Height: h,
  			Data:   icon[(start + 2):(start + upto + 2)],
  		}
  		wmicons = append(wmicons, wmicon)
  
  		start += upto + 2
  	}
  
  	return wmicons, nil
  }
docs: // _NET_WM_ICON get