code: function (eventName, data) {
              this._queueOrExecute(function () {
  
                  this.trackEvent(eventName, data);
              });
  
              this._debug('trackEvent: ' + [eventName, JSON.stringify(data || {})].join(', '));
  
              if (typeof qaContext !== "undefined" && qaContext.getTrackings()) {
                  try {
                      qaContext.getTrackings().push({
                          service: "optimizely",
                          type: "event",
                          data: {
                              eventName: eventName,
                              data: data
                          }
                      });
                  } catch (e) {
                  }
              }
  
          }
docs: *
  Track custom events in Optimizely. The event "eventName" will be tracked and associated with the current visitor.
  
  @param {String} eventName
  @param {Object} [data]
  @see https://www.optimizely.com/docs/api#track-event