apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/NamespaceBranchService.java/NamespaceBranchService/updateBranchGrayRules
class NamespaceBranchService:  public void updateBranchGrayRules(String appId, Env env, String clusterName, String namespaceName,
                                    String branchName, GrayReleaseRuleDTO rules, String operator) {
    rules.setDataChangeCreatedBy(operator);
    rules.setDataChangeLastModifiedBy(operator);

    namespaceBranchAPI.updateBranchGrayRules(appId, env, clusterName, namespaceName, branchName, rules);

    Tracer.logEvent(TracerEventType.UPDATE_GRAY_RELEASE_RULE,
            String.format("%s+%s+%s+%s", appId, env, clusterName, namespaceName));
  }