CallsMoveToContent and tests if the current content node is a start tag or emptyelementtag.
测试当前内容节点是否是开始标记。
2
Remember, the DOM will create well-formed HTML, meaning that the element is currently empty, with both a starting and ending tag.
要记住,DOM会创建结构良好的HTML,就是说这个目前为空的元素包括起始和结束标签。
3
Moreover, an element that has no content is represented by an empty child list, but a self-closed tag is represented by None. Listing 2 shows this structure in action.