code: public function setAttributes(array $attr, $ns = null)
      {
          $dom = dom_import_simplexml($this);
          foreach ($attr as $k => $v) {
              $dom->setAttributeNS($ns, $k, $v);
          }
          return $this;
      }
docs: Set several attributes at once
  
  @param    array $attr Attributes as name => value pairs
  @param    string $ns Namespace for the attributes
  @return    SimpleDOM            Current node