@Override
  public String toString() {
    return String.format("AsyncIoTConsensusServiceClient{%s}", endpoint);
  }
return self, the method doesn't need to be called by the user and will be triggered after the
RPC is finished.
iotdb-core/consensus/src/main/java/org/apache/iotdb/consensus/iot/client/AsyncIoTConsensusServiceClient.java