isHtmlElement = (value) => {
  return goog.isObject(value) && isElement(value) &&
      // namespaceURI of old browsers (FF < 3.6, IE < 9) will be null.
      (!/** @type {!Element} */ (value).namespaceURI ||
       /** @type {!Element} */ (value).namespaceURI === HTML_NAMESPACE);
}
Determines if a value is a DOM HTML Element.
@param {*} value
@return {boolean}