@Test @Ignore
public void testReadFromDisk() {

    Set<Car> collectionOfCars = CarFactory.createCollectionOfCars(50);
    Set<Integer> expectedCarIds = collectionOfCars.stream().map(Car::getCarId).collect(toSet());
    File persistenceFile = new File("cqengine-persisted.dat");
    System.out.println("Persistence file: " + persistenceFile.getAbsolutePath());
    // Create a collection (it will read from the pre-existing file on disk)...
    DiskPersistence<Car, Integer> persistence = DiskPersistence.onPrimaryKeyInFile(Car.CAR_ID, persistenceFile);
    IndexedCollection<Car> cars = new ConcurrentIndexedCollection<Car>(persistence);
    // Retrieve the cars from disk...
    Set<Integer> actualCarIds = cars.stream().map(Car::getCarId).collect(toSet());
    Assert.assertEquals(expectedCarIds, actualCarIds);
    System.out.println("Loaded from disk: " + actualCarIds);
}