Set<MACAddress> oldXboxes = new HashSet<MACAddress>();
    Set<MACAddress> newXboxes = new HashSet<MACAddress>();
    
    oldXboxes = xbList.loadFromFile();
    if(true) {  // if the user wants to detect more xboxes
    	newXboxes = XboxList.findXboxes(device);
    }
    newXboxes.addAll(oldXboxes);