protected boolean tryTransfer(
      final AsyncPipeDataTransferServiceClient client, final TPipeTransferReq req)
      throws TException {
    // track handler before checking if connector is closed
    connector.trackHandler(this);
    if (connector.isClosed()) {
      clearEventsReferenceCount();
      connector.eliminateHandler(this);
      return false;
    }
    doTransfer(client, req);
    return true;
  }
Attempts to transfer data using the provided client and request.

@param client the client used for data transfer
@param req the request containing transfer details
@return {@code true} if the transfer was initiated successfully, {@code false} if the connector
    is closed
@throws TException if an error occurs during the transfer
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/pipe/connector/protocol/thrift/async/handler/PipeTransferTrackableHandler.java