docs: public void addPayloadProperties(Object msg, BaseMessage message)
      {
          MessageDataDesc messageDataDesc = message.getMessageDataDesc(null);   // Top level only
          if (messageDataDesc != null)
          {
              Map<String,Class<?>> mapPropertyNames = messageDataDesc.getPayloadPropertyNames(null);
          
              if (mapPropertyNames != null)
              {
                  Map<String,Object> properties = this.getPayloadProperties(msg, mapPropertyNames);
                  for (String key : properties.keySet())
                  {
                      message.put(key, properties.get(key));
                  }
              }
          }
      }