@Override
    public boolean validateObject(
        TEndPoint endPoint, PooledObject<AsyncDataNodeExternalServiceClient> pooledObject) {
      return pooledObject.getObject().isReady();
    }
return self, the method doesn't need to be called by the user and will be triggered after the
RPC is finished.
iotdb-core/node-commons/src/main/java/org/apache/iotdb/commons/client/async/AsyncDataNodeExternalServiceClient.java