private List<Integer> getBeSeqIndexes(List<Long> flatBackendsPerBucketSeq, long beId) {
        return IntStream.range(0, flatBackendsPerBucketSeq.size()).boxed().filter(
                idx -> flatBackendsPerBucketSeq.get(idx).equals(beId)).collect(Collectors.toList());
    }
@Test
    public void testGetBeSeqIndexes() {
        List<Long> flatBackendsPerBucketSeq = Lists.newArrayList(1L, 2L, 2L, 3L, 4L, 2L);
        List<Integer> indexes = Deencapsulation.invoke(balancer,
                "getBeSeqIndexes", flatBackendsPerBucketSeq, 2L);
        Assert.assertArrayEquals(new int[] {1, 2, 5}, indexes.stream().mapToInt(i -> i).toArray());
        System.out.println("backend1 id is " + backend1.getId());
    }