(PHP 5, PHP 7)
DOMElement::getAttributeNodeNS — Returns attribute node
   Returns the attribute node in namespace namespaceURI 
   with local name localName for the current node.
  
namespaceURIThe namespace URI.
localNameThe local name.
The attribute node. Note that for XML namespace declarations (xmlns and xmlns:* attributes) an instance of DOMNameSpaceNode is returned instead of a DOMAttr.