code: public TrxMessageHeader addMessageProperties(TrxMessageHeader trxMessageHeader)
      {
          Map<String,Object> mapHeaderMessageTransport = trxMessageHeader.getMessageTransportMap();
          
          Map<String,Object> propMessageTransport = ((PropertiesField)this.getField(MessageTransport.PROPERTIES)).loadProperties();
          String strSendBy = this.getField(MessageTransport.CODE).toString();
          if ((strSendBy != null) && (strSendBy.length() > 0))
              propMessageTransport.put(MessageTransport.SEND_MESSAGE_BY_PARAM, strSendBy);
          String strTransType = this.getField(MessageTransport.MESSAGE_TRANSPORT_TYPE).toString();
          if ((strTransType != null) && (strTransType.length() > 0))
              propMessageTransport.put(MessageTransport.TRANSPORT_TYPE_PARAM, strTransType);
          propMessageTransport.put(MessageTransport.TRANSPORT_ID_PARAM, this.getField(MessageTransport.ID).toString());
          if (mapHeaderMessageTransport != null)
              Utility.putAllIfNew(mapHeaderMessageTransport, propMessageTransport);
          else
              mapHeaderMessageTransport = propMessageTransport;
          trxMessageHeader.setMessageTransportMap(mapHeaderMessageTransport);
          
          return trxMessageHeader;
      }
docs: Add the properties to this message (transportinfo).
  NOTE: The properties are added ONLY if they don't currently exist in the transport map.