code: function getIncludeTemplateElement(tplFile) {
      let ast = tplFile.ast;
      if (!ast) {
          ast = tplFile.ast = parseDom(tplFile.content.toString());
      }
  
      let children = ast.children;
      for (let i = 0, len = children.length; i < len; i++) {
          let node = children[i];
          if (node.type === 'tag' && node.name === 'template') {
              return node;
          }
      }
  }
docs: Get included template element
  
  @inner
  @param {Object} tplFile the included template file
  @return {?Object}