https://github.com/apache/incubator-dubbo/blob/3e9b66854c6f70b1dfa7dd19e689bd04ae0ecb41/dubbo-registry/dubbo-registry-redis/src/main/java/com/alibaba/dubbo/registry/redis/RedisRegistry.java#L590

https://github.com/apache/incubator-dubbo/blob/3e9b66854c6f70b1dfa7dd19e689bd04ae0ecb41/dubbo-registry/dubbo-registry-redis/src/main/java/com/alibaba/dubbo/registry/redis/RedisRegistry.java#L602

Just read the RedisRegistry.java and got doubtful about the above lines. Is the following code more appropriate ?

```
if (first) {
   // blah blah												
} 
```



import org.apache.dubbo.common.utils.StringUtils;
import org.apache.dubbo.common.utils.UrlUtils;
import org.apache.dubbo.registry.NotifyListener;
import org.apache.dubbo.registry.support.FailbackRegistry;
import org.apache.dubbo.rpc.RpcException;
import redis.clients.jedis.Jedis;
import redis.clients.jedis.JedisPool;
import redis.clients.jedis.JedisPubSub;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
/**
 * RedisRegistry
 */
public class RedisRegistry extends FailbackRegistry {