apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/NamespaceService.java/NamespaceService/deleteByAppIdAndClusterName
class NamespaceService:  @Transactional
  public void deleteByAppIdAndClusterName(String appId, String clusterName, String operator) {

    List<Namespace> toDeleteNamespaces = findNamespaces(appId, clusterName);

    for (Namespace namespace : toDeleteNamespaces) {

      deleteNamespace(namespace, operator);

    }
  }