code: function() {
          var deactivated = OpenLayers.Strategy.prototype.deactivate.call(this);
          if(deactivated) {
              this.layer.events.un({
                  "moveend": this.update,
                  "refresh": this.update,
                  "visibilitychanged": this.update,
                  scope: this
              });
          }
          return deactivated;
      }
docs: Method: deactivate
  Tear down strategy with regard to reading new batches of remote data.
  
  Returns:
  {Boolean} The strategy was successfully deactivated.