code: function(err, objs) {
          that.worker = null;
          if(err) {
            that.setError(err);
            that.setStatus("Error.");
            that.state = 3; // incomplete
          } else {
            that.setCurrentObjects(objs);
            that.setStatus("Ready.");
            that.state = 2; // complete
          }
          that.enableItems();
        }
docs: handle the results