apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/api/AdminServiceAPI.java/NamespaceBranchAPI/updateBranchGrayRules
class NamespaceBranchAPI:    public void updateBranchGrayRules(String appId, Env env, String clusterName,
        String namespaceName, String branchName, GrayReleaseRuleDTO rules) {
      restTemplate
          .put(env, "/apps/{appId}/clusters/{clusterName}/namespaces/{namespaceName}/branches/{branchName}/rules",
              rules, appId, clusterName, namespaceName, branchName);

    }