docs: function(options) {
          OpenLayers.Control.Panel.prototype.initialize.apply(this, [options]);
          var options = {
              slideFactor: this.slideFactor,
              slideRatio: this.slideRatio
          };
          this.addControls([
              new OpenLayers.Control.Pan(OpenLayers.Control.Pan.NORTH, options),
              new OpenLayers.Control.Pan(OpenLayers.Control.Pan.SOUTH, options),
              new OpenLayers.Control.Pan(OpenLayers.Control.Pan.EAST, options),
              new OpenLayers.Control.Pan(OpenLayers.Control.Pan.WEST, options)
          ]);
      }