code: function() {
          var deactivated = OpenLayers.Strategy.prototype.deactivate.call(this);
          if(deactivated) {
              this.clearCache();
              this.layer.events.un({
                  "beforefeaturesadded": this.cacheFeatures,
                  scope: this
              });
          }
          return deactivated;
      }
docs: APIMethod: deactivate
  Deactivate the strategy.  Unregister any listeners, do appropriate
  tear-down.
  
  Returns:
  {Boolean} The strategy was successfully deactivated.