public String getNextId() {
        return String.format("%s-%d-%d", prefix, generatorInstanceId, counter.getAndIncrement());
    }
@Test
    public void invalidZnode() throws Exception {
        store.put("/my/test/invalid", "invalid-number".getBytes(), Optional.of(-1L));

        DistributedIdGenerator gen = new DistributedIdGenerator(coordinationService, "/my/test/invalid", "p");

        // It should not get exception if content is there
        assertEquals(gen.getNextId(), "p-0-0");
    }