apollo-configservice/src/main/java/com/ctrip/framework/apollo/configservice/service/ReleaseMessageServiceWithCache.java/ReleaseMessageServiceWithCache/findLatestReleaseMessageForMessages
class ReleaseMessageServiceWithCache:  public ReleaseMessage findLatestReleaseMessageForMessages(Set<String> messages) {
    if (CollectionUtils.isEmpty(messages)) {
      return null;
    }

    long maxReleaseMessageId = 0;
    ReleaseMessage result = null;
    for (String message : messages) {
      ReleaseMessage releaseMessage = releaseMessageCache.get(message);
      if (releaseMessage != null && releaseMessage.getId() > maxReleaseMessageId) {
        maxReleaseMessageId = releaseMessage.getId();
        result = releaseMessage;
      }
    }

    return result;
  }