code: public final String getExceptionMessage() {
          /* If the Exception information is set, return the translated message */
          if (getHdr2().getChoiceField(JsHdr2Access.EXCEPTION) != JsHdr2Access.IS_EXCEPTION_EMPTY) {
              return exceptionMessages.getFormattedMessage(MfpConstants.EXCEPTION_MESSAGE_KEY_PREFIX + getExceptionReason().toString()
                                                           , getExceptionInserts()
                                                           , "Failed to deliver message, rc=" + getExceptionReason() + ". Inserts: " + Arrays.asList(getExceptionInserts())
                              );
          }
          /* If no, just return null. */
          else {
              return null;
          }
      }
docs: /*
  Get the Exception Message for the message.
  
  Javadoc description supplied by JsMessage interface.