code: function _checkContentElem(obj, parent, tmplRule, hasExProps, noSplitNewline) {
    if (!parent.content) {
      parent.content = [];
    }
  
    tools.each(obj, (item, i, l) => {
      checkElem(item, parent, tmplRule, hasExProps, noSplitNewline, i == l - 1);
    }, true);
  }
docs: 检测子元素节点