apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/grayReleaseRule/GrayReleaseRulesHolder.java/GrayReleaseRulesHolder/addCache
class GrayReleaseRulesHolder:  private void addCache(String key, GrayReleaseRuleCache ruleCache) {
    if (ruleCache.getBranchStatus() == NamespaceBranchStatus.ACTIVE) {
      for (GrayReleaseRuleItemDTO ruleItemDTO : ruleCache.getRuleItems()) {
        for (String clientIp : ruleItemDTO.getClientIpList()) {
          reversedGrayReleaseRuleCache.put(assembleReversedGrayReleaseRuleKey(ruleItemDTO
              .getClientAppId(), ruleCache.getNamespaceName(), clientIp), ruleCache.getRuleId());
        }
      }
    }
    grayReleaseRuleCache.put(key, ruleCache);
  }