code: function () {
          for (var e in this.extensions) {
              if (typeof this.extensions[e] !== "boolean") {
                  this.extensions[e].destroy();
              }
          }
          this.extensions = null;
          if (this.element) {
              OpenLayers.Event.stopObservingElement(this.element);
              if(this.element.hasScrollEvent) {
                  OpenLayers.Event.stopObserving(
                      window, "scroll", this.clearMouseListener
                  );
              }
          }
          this.element = null;
  
          this.listeners = null;
          this.object = null;
          this.fallThrough = null;
          this.eventHandler = null;
      }
docs: APIMethod: destroy