code: func detach(xu *xgbutil.XUtil, evtype int, win xproto.Window) {
  	mkeys := keyKeys(xu)
  	detachKeyBindWindow(xu, evtype, win)
  	for _, key := range mkeys {
  		if keyBindGrabs(xu, key.Evtype, key.Win, key.Mod, key.Code) == 0 {
  			Ungrab(xu, key.Win, key.Mod, key.Code)
  		}
  	}
  }
docs: // detach removes all handlers for the provided window and event type
  // combination. This will also issue an ungrab request for each grab that
  // drops to zero.