(PHP 5, PHP 7, PHP 8)
DOMElement::hasAttributeNS — Checks to see if attribute exists
$namespace, string $localName): bool
   Indicates whether attribute in namespace namespace 
   named localName exists as a member of the element.
  
namespaceThe namespace URI.
localNameThe local name.
   成功時返回 true, 或者在失敗時返回 false。