docs: public TrxMessageHeader addMessageProperties(TrxMessageHeader trxMessageHeader)
      {
          Map<String,Object> mapHeaderMessageInfo = trxMessageHeader.getMessageInfoMap();
          
          Map<String,Object> propMessageTransportInfo = ((PropertiesField)this.getField(MessageTransportInfo.PROPERTIES)).loadProperties();
          if (mapHeaderMessageInfo != null)
              mapHeaderMessageInfo.putAll(propMessageTransportInfo);
          else
              mapHeaderMessageInfo = propMessageTransportInfo;
          trxMessageHeader.setMessageInfoMap(mapHeaderMessageInfo);
          
          return trxMessageHeader;
      }