docs: function(size) { 
          if (this.singleTile) {
              size = this.map.getSize();
              size.h = parseInt(size.h * this.ratio, 10);
              size.w = parseInt(size.w * this.ratio, 10);
          } 
          OpenLayers.Layer.HTTPRequest.prototype.setTileSize.apply(this, [size]);
      }