docs: function(extent, resolutionChanged) {
          this.extent = extent.clone();
          if (this.map.baseLayer && this.map.baseLayer.wrapDateLine) {
              var ratio = extent.getWidth() / this.map.getExtent().getWidth(),
                  extent = extent.scale(1 / ratio);
              this.extent = extent.wrapDateLine(this.map.getMaxExtent()).scale(ratio);
          }
          if (resolutionChanged) {
              this.resolution = null;
          }
          return true;
      }