public InstanceStats getStats(ServiceInstance serviceInstance) {
        try {
            return instanceStatsCache.get(serviceInstance);
        } catch (ExecutionException e) {
            InstanceStats stats = createStats();
            instanceStatsCache.asMap().putIfAbsent(serviceInstance, stats);
            return stats;
        }
    }
@Test
    public void getStats() {
        final ServiceStats serviceStats = new ServiceStats(serviceName);
        final InstanceStats stats = serviceStats.getStats(CommonUtils.buildInstance(serviceName, 8080));
        Assert.assertNotNull(stats);
        final Optional<Object> createStats = ReflectUtils.invokeMethod(serviceStats, "createStats", null, null);
        Assert.assertTrue(createStats.isPresent());
    }