code: function(node, uri, name, value) {
          if(node.setAttributeNS) {
              node.setAttributeNS(uri, name, value);
          } else {
              if(this.xmldom) {
                  if(uri) {
                      var attribute = node.ownerDocument.createNode(
                          2, name, uri
                      );
                      attribute.nodeValue = value;
                      node.setAttributeNode(attribute);
                  } else {
                      node.setAttribute(name, value);
                  }
              } else {
                  throw "setAttributeNS not implemented";
              }
          }
      }
docs: APIMethod: setAttributeNS
  Adds a new attribute or changes the value of an attribute with the given
  namespace and name.
  
  Parameters:
  node - {Element} Element node on which to set the attribute.
  uri - {String} Namespace URI for the attribute.
  name - {String} Qualified name (prefix:localname) for the attribute.
  value - {String} Attribute value.