code: @Override
      public void addComment(XmlElement xmlElement) {
          Map<String, Object> map = new HashMap<>();
          map.put("mgb", MergeConstants.NEW_ELEMENT_TAG);
          map.put("xmlElement", xmlElement);
  
          // 添加评论
          addXmlElementComment(xmlElement, map, EnumNode.ADD_COMMENT);
      }
docs: This method should add a suitable comment as a child element of the specified xmlElement to warn users that the
  element was generated and is subject to regeneration.
  
  @param xmlElement
  the xml element