public List<String> findConsumerIdList(final String topic, final String group) {
        String brokerAddr = this.findBrokerAddrByTopic(topic);
        if (null == brokerAddr) {
            this.updateTopicRouteInfoFromNameServer(topic);
            brokerAddr = this.findBrokerAddrByTopic(topic);
        }

        if (null != brokerAddr) {
            try {
                return this.mQClientAPIImpl.getConsumerIdListByGroup(brokerAddr, group, clientConfig.getMqClientApiTimeout());
            } catch (Exception e) {
                log.warn("getConsumerIdListByGroup exception, " + brokerAddr + " " + group, e);
            }
        }

        return null;
    }
@Test
    public void testFindConsumerIdList() {
        topicRouteTable.put(topic, createTopicRouteData());
        brokerAddrTable.put(defaultBroker, createBrokerAddrMap());
        consumerTable.put(group, createMQConsumerInner());
        List<String> actual = mqClientInstance.findConsumerIdList(topic, group);
        assertNotNull(actual);
        assertEquals(0, actual.size());
    }