code: @Override
      public UndeliverableReturnCode handleUndeliverableMessage(
                                                                SIBusMessage msg,
                                                                String alternateUser,
                                                                TransactionCommon tran,
                                                                int exceptionReason,
                                                                String[] exceptionStrings)
      {
          // F001333-14610
          // Delegate down onto the new method passing a null
          // subscription ID.
          return handleUndeliverableMessage(msg, alternateUser, tran, exceptionReason, exceptionStrings, null);
      }
docs: Wrapper method for handleUndeliverableMessage. This version will be called
  from an external component via the
  com.ibm.ws.sib.processor.ExceptionDestinationHandler interface. E.g. we
  need to access this routine from the MQLink in the comms component.
  
  @param msg - The undeliverable message
  @param tran - The transaction that the message was delivered under
  @param exceptionReason - The reason why the message could not be delivered
  @param exceptionStrings - A list of inserts to place into an error message
  @return A code indicating what we did with the message