code: function() {
          var deactivated = false;
          if (OpenLayers.Handler.prototype.deactivate.apply(this, arguments)) {
              for (var i=0, len=this.KEY_EVENTS.length; i<len; i++) {
                  OpenLayers.Event.stopObserving(
                      this.observeElement, this.KEY_EVENTS[i], this.eventListener);
              }
              deactivated = true;
          }
          return deactivated;
      }
docs: Method: deactivate