@Test public void testNullifyImages() { PwFloor floor1 = (new Gson()).fromJson(floor_2_resources, PwFloor.class); floor1.nullifyImages(); ArrayList<PwFloorResource> floorResourceArrayList = floor1.getResources(); for (PwFloorResource floorResource : floorResourceArrayList) { assertNull(floorResource.getPicture()); } }