code: public void extendedGet(String remoteFileName,
                              long size,
                              DataSink sink,
                              MarkerListener mListener)
          throws IOException,
                 ClientException,
                 ServerException {
          extendedGet(remoteFileName,
                      0,
                      size,
                      sink,
                      mListener);
      }
docs: Performs extended retrieve (partial retrieve mode starting
  at offset 0).
  
  @param remoteFileName file to retrieve
  @param size number of bytes of remote file to transmit
  @param sink data sink to store the file
  @param mListener marker listener