code: function() {
          // for now, nothing special to do here.
          OpenLayers.Layer.Grid.prototype.destroy.apply(this, arguments);
  
          // Remove from memory the Zoomify pyramid - is that enough?
          this.tileCountUpToTier.length = 0;
          this.tierSizeInTiles.length = 0;
          this.tierImageSize.length = 0;
  
      }
docs: APIMethod:destroy