code: function() {
          if (!OpenLayers.Format.XML.document && !this.xmldom) {
              if (document.implementation && document.implementation.createDocument) {
                  OpenLayers.Format.XML.document =
                      document.implementation.createDocument("", "", null);
              } else if (!this.xmldom && window.ActiveXObject) {
                  this.xmldom = new ActiveXObject("Microsoft.XMLDOM");
              }
          }
          return OpenLayers.Format.XML.document || this.xmldom;
      }
docs: Method: getXMLDoc
  Get an XML document for nodes that are not supported in HTML (e.g.
  createCDATASection). On IE, this will either return an existing or
  create a new <xmldom> on the instance. On other browsers, this will
  either return an existing or create a new shared document (see
  <OpenLayers.Format.XML.document>).
  
  Returns:
  {XMLDocument}