code: public DataChannelReader getDataChannelSource(TransferContext context)
  	throws Exception {
  	String id = getHandlerID(session.transferMode, session.transferType, SOURCE);
  	logger.debug("type/mode: " + id);
  	Class clazz = (Class)dataHandlers.get(id);
  	if (clazz == null) {
  	    throw new Exception("No data reader for type/mode" + id);
  	}
  	DataChannelReader reader =  (DataChannelReader)clazz.newInstance();
  	if (reader instanceof EBlockAware) {
  	    ((EBlockAware)reader).setTransferContext((EBlockParallelTransferContext)context);
  	}
  	return reader;
      }
docs: currently context is only needed in case of EBlock mode