(PHP 5, PHP 7)
DOMXPath::registerNamespace — Registers the namespace with the DOMXPath object
$prefix
   , string $namespaceURI      
   )
   Registers the namespaceURI and 
   prefix with the DOMXPath object.
  
prefixThe prefix.
namespaceURIThe URI of the namespace.
   Returns TRUE on success or FALSE on failure.