The first element, in tree order, below (not including) the given node whose id matches the given value, or null
when there is none. Shared by Document and DocumentFragment, which both implement the DOM's NonElementParentNode
mixin (so ShadowRoot, a DocumentFragment, gets it too).
The first element, in tree order, below (not including) the given node whose id matches the given value, or null when there is none. Shared by Document and DocumentFragment, which both implement the DOM's NonElementParentNode mixin (so ShadowRoot, a DocumentFragment, gets it too).