apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/service/NamespaceService.java/NamespaceService/findPublicNamespaceForAssociatedNamespace
class NamespaceService:  public NamespaceBO findPublicNamespaceForAssociatedNamespace(Env env, String appId,
      String clusterName, String namespaceName) {
    NamespaceDTO namespace =
        namespaceAPI
            .findPublicNamespaceForAssociatedNamespace(env, appId, clusterName, namespaceName);

    return transformNamespace2BO(env, namespace);
  }