Почему parseInt (1/0, 19) возвращает 18?

Этот скрипт работает для всей версии Android, и я нахожу его после многих поисков

LocationManager locMan;
    String[] mockProviders = {LocationManager.GPS_PROVIDER, LocationManager.NETWORK_PROVIDER};

    try {
        locMan = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

        for (String p : mockProviders) {
            if (p.contentEquals(LocationManager.GPS_PROVIDER))
                locMan.addTestProvider(p, false, false, false, false, true, true, true, 1,
                        android.hardware.SensorManager.SENSOR_STATUS_ACCURACY_HIGH);
            else
                locMan.addTestProvider(p, false, false, false, false, true, true, true, 1,
                        android.hardware.SensorManager.SENSOR_STATUS_ACCURACY_LOW);

            locMan.setTestProviderEnabled(p, true);
            locMan.setTestProviderStatus(p, android.location.LocationProvider.AVAILABLE, Bundle.EMPTY,
                    java.lang.System.currentTimeMillis());
        }
    } catch (Exception ignored) {
        // here you should show dialog which is mean the mock location is not enable
    }