code: func ActivePIDC(pid int32, args ...int) {
  	var hwnd int
  	if len(args) > 0 {
  		hwnd = args[0]
  
  		internalActive(pid, hwnd)
  		return
  	}
  
  	xid, err := GetXId(xu, pid)
  	if err != nil {
  		log.Println("GetXidFromPid errors is: ", err)
  		return
  	}
  
  	internalActive(int32(xid), hwnd)
  }
docs: // ActivePIDC active the window by PID,
  // If args[0] > 0 on the unix platform via a xid to active