code: function serializeTag(elem, opts) {
      // Handle SVG
      if (elem.name === 'svg') {
          opts = {decodeEntities: opts.decodeEntities, xmlMode: true};
      }
  
      let tag = '<' + elem.name;
      let attribs = serializeAttrs(elem.attribs, opts);
  
      if (attribs) {
          tag += ' ' + attribs;
      }
  
      let closeAllTag = opts.xmlMode;
      let isSingleTag = singleTag[elem.name];
      let hasChildren = elem.children && elem.children.length;
      let endTag = '</' + elem.name + '>';
      if (hasChildren) {
          tag += '>';
          tag += serializeDom(elem.children, opts);
          tag += endTag;
      }
      else if (closeAllTag || !isSingleTag) {
          if (isSingleTag || elem.isSelfClose) {
              tag += '/>';
          }
          else {
              tag += '>' + endTag;
          }
      }
      else {
          tag += '>';
      }
  
      return tag;
  }
docs: Serialize tag
  
  @inner
  @param {Object} elem the tag to serialize
  @param {Object} opts the serialize options
  @return {string}