code: public TransferState asynchGet(String remoteFileName,
                                     DataSink sink,
                                     MarkerListener mListener)
          throws IOException, ClientException, ServerException {
          checkTransferParamsGet();
  
          localServer.store(sink);
          controlChannel.write(new Command("RETR", remoteFileName));
  
          return transferStart(localServer.getControlChannel(), mListener);
      }
docs: Retrieves the file from the remote server.
  @param remoteFileName remote file name
  @param sink sink to which the data will be written
  @param mListener restart marker listener (currently not used)