code: public String getSystemMessageId() {
      //based on com.ibm.ws.sib.mfp.impl.JsHdrsImpl
      if (uuid != null) {
        StringBuilder buff = new StringBuilder(uuid.toString());
        buff.append(MfpConstants.MESSAGE_HANDLE_SEPARATOR);
        buff.append(value);
        return new String(buff);
      }
      else {
        return null;
      }
    }
docs: Returns the SIMessageHandles System Message ID.
  
  @return String The SystemMessageID of the SIMessageHandle.