void () { final HashSet<Integer> data = new HashSet<>(); for (int i = 0; i < 5000; i = (int)(i * 1.21 + 3)) { data.add(i); myInstance.add(i); } assertEquals(data.size(), myInstance.size()); for (IntIdsIterator it = myInstance.intIterator(); it.hasNext(); ) { int value = it.next(); assertContainsElements(data, value); data.remove(value); } assertEmpty(data); }