public ParkingSpot searchParkingSpot(ParkingUser user)
    {
        TreeSet<ParkingSpot> userType = garage.get(user.toString());
        ParkingSpot spot = null;
        for(ParkingSpot x: userType)
            if(x.isAvailable() && x.isConnected())
            {
                spot = x;
                break;
            }
                
        return spot;
    }