code: public String[] black_box(final Connection connection, final int length) throws DevFailed {
  		checkIfTango(connection, "black_box");
  
  		build_connection(connection);
  
  		String[] result = new String[0];
  		try {
  	    	result = connection.device.black_box(length);
  		} catch (final DevFailed e) {
  	    	final String reason = "TangoApi_CANNOT_READ_BLACK BOX";
  	    	final String desc = "Cannot read black box on " + connection.devname;
  	    	final String origin = "Connection.black_box()";
  	    	Except.throw_connection_failed(e, reason, desc, origin);
  		} catch (final Exception e) {
  	    	ApiUtilDAODefaultImpl.removePendingRepliesOfDevice(connection);
  	    	throw_dev_failed(connection, e, "black_box", false);
  		}
  		return result;
      }
docs: ===========================================================