Scanning / x Drones Detected #62

I'm trying to alter the code slightly so when no drones are detected, it stated "Scanning", however when it detects a drone, it displays 1 Drone Detected for example.

This is what I have for DebugActivity.java but it always seems to default to 0 Drones Detected instead of Scanning, any ideas please?

` private void initialize() {
mModel.setAllAircraft(dataManager.getAircraft());

    final Observer<Set<AircraftObject>> listObserver = airCrafts -> {
        if (airCrafts == null) {
            setTitle(String.format(Locale.US, "Scanning...", airCrafts.size()));
    } else if (airCrafts != null) {
            setTitle(String.format(Locale.US, "%d Drones Detected", airCrafts.size()));
        }
    };`