private void transfer(final PipeConsensusDeleteEventHandler pipeConsensusDeleteEventHandler) {
    AsyncPipeConsensusServiceClient client = null;
    try {
      client = asyncTransferClientManager.borrowClient(getFollowerUrl());
      pipeConsensusDeleteEventHandler.transfer(client);
    } catch (final Exception ex) {
      logOnClientException(client, ex);
      pipeConsensusDeleteEventHandler.onError(ex);
    }
  }
PipeConsensus only need transfer heartbeat event here. And heartbeat event doesn't need to be
added to transferBuffer.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/connector/protocol/pipeconsensus/PipeConsensusAsyncConnector.java