docs: 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;
      }