Car car = new Car();
Collection<Part> ep = new ArrayList<Part>();
for (int i=0; i < 4; i++) {
ep.add(new Wheel());
}
ep.add(new CustomPart(false));
car.setExpensiveParts(ep);
car = serDeser(car, Car.class);
Assert.assertEquals(5, car.getExpensiveParts().size());
List<Part> list = new ArrayList<Part>(car.getExpensiveParts());
Assert.assertEquals(true, list.get(3).isReplaceable());