// Note: The spec says "the XPathEvaluator interface will be implemented on the
// same object which implements the Document interface" and does not define a
// constructor or other means to create an XPathEvaluator object. Nonetheless,
// Blink, Gecko, Presto, WebKit and all have these APIs on both Document and the
// constructable XPathEvaluator interface.
[2] Align with IDL constructor changes (autokagami著, ) https://github.com/whatwg/dom/commit/57512fac17cf2f1c4c85be4aec178c8086ee5ee4
[3] Update to constructor operations · Issue #780 · whatwg/dom () https://github.com/whatwg/dom/issues/780
[4] Add the DOM XPath interfaces from the WHATWG wiki (annevk著, ) https://github.com/whatwg/dom/commit/dea5d92156f144faf57d1a5e54a17227139ca3c5