@Override
    public boolean remove(Object o) {
        if (!(o instanceof Integer)) {
            throw new ClassCastException("PartitionIdSet can be only used with Integers");
        }
        return remove(((Integer) o).intValue());
    }
@Test(expected = ClassCastException.class)
    public void test_remove_whenNotInteger() {
        partitionIdSet.remove(new Object());
    }