code: func WmIconSizeSet(xu *xgbutil.XUtil, win xproto.Window,
  	icondim *IconSize) error {
  
  	raw := []uint{
  		icondim.MinWidth, icondim.MinHeight,
  		icondim.MaxWidth, icondim.MaxHeight,
  		icondim.WidthInc, icondim.HeightInc,
  	}
  
  	return xprop.ChangeProp32(xu, win, "WM_ICON_SIZE", "WM_ICON_SIZE", raw...)
  }
docs: // WM_ICON_SIZE set