這個 CSS4 (draft) 的特性目前還沒有瀏覽器支援，所以 uBlock Origin 決定自己來：
This is a planned CSS4 operator, but no browser supports it yet. I decided to go ahead and implement it so that it can already be used. See The Relational Pseudo-class: :has() in the Selector Level 4/Editor's Draft.
由於效能問題，要求一定要有 hostname，而不能是 global rule：
uBO's implementation is simplified so as to ensure performance. The :has operator must be used with at least one hostname (it must be specific), and must be of the form (example)[.]
這對於 html block 長的幾乎一樣，只有在某個地方多出
Promoted by ... 之類的結構處理起來很方便，可以拿來找出「裡面有廣告
Promoted by ...，而是連廣告內容都拿掉)