code: function (obj) {
          if (obj == null) {
              obj = new OpenLayers.Layer.UTFGrid(this.getOptions());
          }
  
          // get all additions from superclasses
          obj = OpenLayers.Layer.Grid.prototype.clone.apply(this, [obj]);
  
          return obj;
      }
docs: APIMethod: clone
  Create a clone of this layer
  
  Parameters:
  obj - {Object} Only used by a subclass of this layer.
  
  Returns:
  {<OpenLayers.Layer.UTFGrid>} An exact clone of this OpenLayers.Layer.UTFGrid