code: int guessPayloadLength() {
      int length = 0;
      // It is likely that the String length will be the same as the length in bytes
      // when it has been encoded (to UTF8) plus a small overhead.
      try {
        if (jmo.getPayloadPart().getChoiceField(JsPayloadAccess.PAYLOAD) != JsPayloadAccess.IS_PAYLOAD_EMPTY) {
          String payload = (String)getPayload().getField(JmsTextBodyAccess.BODY_DATA_VALUE);
          if (payload != null) length = payload.length() + 24;
        }
      }
      catch (MFPUnsupportedEncodingRuntimeException e) {
        FFDCFilter.processException(e, "com.ibm.ws.sib.mfp.impl.JsJmsTextMessageImpl.getText", "129");
        // hmm... how do we figure out a reasonable length
      }
      return length;
    }
docs: /*
  Provide an estimate of encoded length of the payload