code: function() {
          // Warning: Layer.Markers.destroy() must be called prior to calling
          // clearFeatures() here, otherwise we leak memory. Indeed, if
          // Layer.Markers.destroy() is called after clearFeatures(), it won't be
          // able to remove the marker image elements from the layer's div since
          // the markers will have been destroyed by clearFeatures().
          OpenLayers.Layer.Markers.prototype.destroy.apply(this, arguments);
          this.clearFeatures();
          this.features = null;
      }
docs: Method: destroy