### Question:
MixAll { public static String brokerVIPChannel(final boolean isChange, final String brokerAddr) { if (isChange) { String[] ipAndPort = brokerAddr.split(":"); String brokerAddrNew = ipAndPort[0] + ":" + (Integer.parseInt(ipAndPort[1]) - 2); return brokerAddrNew; } else { return brokerAddr; } }  static String getWSAddr(); static String getRetryTopic(final String consumerGroup); static boolean isSysConsumerGroup(final String consumerGroup); static boolean isSystemTopic(final String topic); static String getDLQTopic(final String consumerGroup); static String brokerVIPChannel(final boolean isChange, final String brokerAddr); static long getPID(); static void string2File(final String str, final String fileName); static void string2FileNotSafe(final String str, final String fileName); static String file2String(final String fileName); static String file2String(final File file); static String file2String(final URL url); static void printObjectProperties(final InternalLogger logger, final Object object); static void printObjectProperties(final InternalLogger logger, final Object object,
        final boolean onlyImportantField); static String properties2String(final Properties properties); static Properties string2Properties(final String str); static Properties object2Properties(final Object object); static void properties2Object(final Properties p, final Object object); static boolean isPropertiesEqual(final Properties p1, final Properties p2); static List<String> getLocalInetAddress(); static String getLocalhostByNetworkInterface(); static boolean compareAndIncreaseOnly(final AtomicLong target, final long value); static String humanReadableByteCount(long bytes, boolean si); static final String ROCKETMQ_HOME_ENV; static final String ROCKETMQ_HOME_PROPERTY; static final String NAMESRV_ADDR_ENV; static final String NAMESRV_ADDR_PROPERTY; static final String MESSAGE_COMPRESS_LEVEL; static final String DEFAULT_NAMESRV_ADDR_LOOKUP; static final String WS_DOMAIN_NAME; static final String WS_DOMAIN_SUBGROUP; static final String AUTO_CREATE_TOPIC_KEY_TOPIC; static final String BENCHMARK_TOPIC; static final String DEFAULT_PRODUCER_GROUP; static final String DEFAULT_CONSUMER_GROUP; static final String TOOLS_CONSUMER_GROUP; static final String FILTERSRV_CONSUMER_GROUP; static final String MONITOR_CONSUMER_GROUP; static final String CLIENT_INNER_PRODUCER_GROUP; static final String SELF_TEST_PRODUCER_GROUP; static final String SELF_TEST_CONSUMER_GROUP; static final String SELF_TEST_TOPIC; static final String OFFSET_MOVED_EVENT; static final String ONS_HTTP_PROXY_GROUP; static final String CID_ONSAPI_PERMISSION_GROUP; static final String CID_ONSAPI_OWNER_GROUP; static final String CID_ONSAPI_PULL_GROUP; static final String CID_RMQ_SYS_PREFIX; static final List<String> LOCAL_INET_ADDRESS; static final String LOCALHOST; static final String DEFAULT_CHARSET; static final long MASTER_ID; static final long CURRENT_JVM_PID; static final String RETRY_GROUP_TOPIC_PREFIX; static final String DLQ_GROUP_TOPIC_PREFIX; static final String SYSTEM_TOPIC_PREFIX; static final String UNIQUE_MSG_QUERY_FLAG; static final String DEFAULT_TRACE_REGION_ID; static final String CONSUME_CONTEXT_TYPE; static final String RMQ_SYS_TRANS_HALF_TOPIC; static final String RMQ_SYS_TRACE_TOPIC; static final String RMQ_SYS_TRANS_OP_HALF_TOPIC; static final String CID_SYS_RMQ_TRANS; }### Answer:
@Test public void testBrokerVIPChannel() { assertThat(MixAll.brokerVIPChannel(true, "127.0.0.1:10911")).isEqualTo("127.0.0.1:10909"); }