This feature is experimental. It may be changed or removed in a future version.
Returns whether the given element has no content.
An element is considered to have content if it has either child elements or non-whitespace text.
<div> elments are all considered empty:
<div></div> <div> </div> <div attr="text"></div>
<div> elements are not considered empty:
<div> Text </div> <div> <span>Text</span> </div> <div> <span></span> </div>
Whether the given element is empty.