The root object of each use-element shadow tree implements the SVGUseElementShadowRoot interface. This interface does not currently define any extensions to the properties and methods defined for the ShadowRoot interface and DocumentOrShadowRoot mixin. However the tree rooted at this node is entirely read-only from the perspective of author scripts....Child nodes include elements, text and comments. Children { get;...generally an element node, a text node, or a comment node. It...