(PHP 5, PHP 7)
The DOMImplementation interface provides a number of methods for performing operations that are independent of any particular instance of the document object model.
$namespaceURI = NULL
   [, string $qualifiedName = NULL
   [, DOMDocumentType $doctype = NULL
  ]]] )$qualifiedName = NULL
   [, string $publicId = NULL
   [, string $systemId = NULL
  ]]] )