code: function (bounds) {
          bounds = this.adjustBounds(bounds);
          var mapRes = this.map.getResolution();
          var scale = Math.round((this.map.getScale() * 10000)) / 10000;
          var pX = Math.round(bounds.left / mapRes);
          var pY = -Math.round(bounds.top / mapRes);
          return this.getFullRequestString(
                        { t: pY, 
                          l: pX,
                          s: scale
                        });
      }
docs: Method: getURL
  
  Parameters:
  bounds - {<OpenLayers.Bounds>}
  
  Returns:
  {String} A string with the layer's url and parameters and also the
  passed-in bounds and appropriate tile size specified as
  parameters