Definition
HTML Standard defines HTMLTemplateElement
[Exposed=Window]
interface HTMLTemplateElement : HTMLElement {
[HTMLConstructor] constructor();
readonly attribute DocumentFragment content;
[CEReactions] attribute DOMString shadowRootMode;
[CEReactions] attribute boolean shadowRootDelegatesFocus;
[CEReactions] attribute boolean shadowRootClonable;
[CEReactions] attribute boolean shadowRootSerializable;
};