How to use the base.merge function in base

data.DEVICE_TYPE = userAgent.DEVICE_TYPE;
        data.BROWSER_TYPE = userAgent.BROWSER_TYPE;
        data.BROWSER_VERSION = userAgent.BROWSER_VERSION;
        data.SIMULATED = userAgent.SIMULATED;

        if (!this.enabled) {
          log(`Skipping event send (no config for current environment): key= ${key} data=`, data);
          continue;
        }

        //for now just send it straight to amplitude - they do their own batching
        // DO THIS BEFORE KEEN PROPERTY
        if(this.amplitudeBlacklist.indexOf(key) === -1)
        {
          // Only send to amplitude if it's not in the blacklist.
          this._amplitudeClient.logEvent(key, merge({}, data));
        }
        
        // Duplicate events over to Facebook pixel if they are on the PIXEL whitelist
        const sendToPixel = this.pixelEnabled && (!this.pixelWhitelist || this.pixelWhitelist.indexOf(key) >= 0);
        if (sendToPixel) {
          pixel.trackCustom(key, merge({}, data));
        }

        const sendToKeen = (!this.keenWhitelist || this.keenWhitelist.indexOf(key) >= 0);
        if (sendToKeen) {
          data.keen = this.keenAddons;
          data.userProperties = merge({}, this.userProperties);

          // special nested ab tests for Keen
          if (GC.app && GC.app.abTests) {
            GC.app.abTests.applyKeenData(data);

setScalingMode (scalingMode, opts) {
    this._scalingMode = scalingMode;

    switch (scalingMode) {
      case SCALING.FIXED:
        opts = merge(opts, {
          width: device.width,
          height: device.height
        });
        break;
      case SCALING.RESIZE:
        opts = merge(opts, { resizeCanvas: true });
      // fall through:
      case SCALING.MANUAL:
        break;
    }

    this._scalingOpts = opts;
    this.onResize();
    setTimeout(bind(this, 'onResize'), 1000);
  }

if(this.amplitudeBlacklist.indexOf(key) === -1)
        {
          // Only send to amplitude if it's not in the blacklist.
          this._amplitudeClient.logEvent(key, merge({}, data));
        }
        
        // Duplicate events over to Facebook pixel if they are on the PIXEL whitelist
        const sendToPixel = this.pixelEnabled && (!this.pixelWhitelist || this.pixelWhitelist.indexOf(key) >= 0);
        if (sendToPixel) {
          pixel.trackCustom(key, merge({}, data));
        }

        const sendToKeen = (!this.keenWhitelist || this.keenWhitelist.indexOf(key) >= 0);
        if (sendToKeen) {
          data.keen = this.keenAddons;
          data.userProperties = merge({}, this.userProperties);

          // special nested ab tests for Keen
          if (GC.app && GC.app.abTests) {
            GC.app.abTests.applyKeenData(data);
          }

          if (!batch[key]) {
            batch[key] = [];
          }
          batch[key].push(data);
        }
      }

      if (Object.keys(batch).length > 0) {
        keen.sendEventBatch(batch);
      }

log(`Skipping event send (no config for current environment): key= ${key} data=`, data);
          continue;
        }

        //for now just send it straight to amplitude - they do their own batching
        // DO THIS BEFORE KEEN PROPERTY
        if(this.amplitudeBlacklist.indexOf(key) === -1)
        {
          // Only send to amplitude if it's not in the blacklist.
          this._amplitudeClient.logEvent(key, merge({}, data));
        }
        
        // Duplicate events over to Facebook pixel if they are on the PIXEL whitelist
        const sendToPixel = this.pixelEnabled && (!this.pixelWhitelist || this.pixelWhitelist.indexOf(key) >= 0);
        if (sendToPixel) {
          pixel.trackCustom(key, merge({}, data));
        }

        const sendToKeen = (!this.keenWhitelist || this.keenWhitelist.indexOf(key) >= 0);
        if (sendToKeen) {
          data.keen = this.keenAddons;
          data.userProperties = merge({}, this.userProperties);

          // special nested ab tests for Keen
          if (GC.app && GC.app.abTests) {
            GC.app.abTests.applyKeenData(data);
          }

          if (!batch[key]) {
            batch[key] = [];
          }
          batch[key].push(data);

initialize(params) {
    this.isInitialized = true;
    this.sessionID = this.createGuid();
    this.userID = params.userID;

    var isDev = userAgent.SIMULATED || process.env.NODE_ENV === 'development';
    this.enabled = !userAgent.SIMULATED && (params.dev || !isDev);

    params = isDev && params.dev ? merge(params.dev, params.prod) : params.prod;

    if (params.pixel && params.pixel.enabled) {
      this.pixelEnabled = params.pixel.enabled && pixel.enabled;
      this.pixelWhitelist = params.pixel.whitelist || [];
    }

    this.keenWhitelist = params.keen.whitelist || [];
    this.amplitudeBlacklist = params.amplitude.blacklist || [];

    if (params.amplitude.key) {
      this._initAmplitude(params.amplitude.key);
    }

    keen.init(params.keen.projectID, params.keen.writeKey);

    this.keenAddons = {

pushError (name, error, event) {
    event = event || {};
    error = error || {};

    logger.error('Sending ERROR:', name, error, event);

    this.pushEvent(name, merge({
      errorCode: error.code || 'No Code',
      errorMessage: error.message || 'No Message',
      errorStack: error.stack || 'No Stack'
    }, event));
  }

updateOpts (opts) {
    this._opts = merge(opts, this._opts);
    if (this._keyListener) {
      this._keyListener.setEnabled(this._opts.keyListenerEnabled);
    }

    if (this._opts.scaleUI) {
      if (Array.isArray(this._opts.scaleUI)) {
        if (this._opts.scaleUI.length != 2) {
          throw new Error('Illegal value for engine option scaleUI: ' +
            this._opts.scaleUI);
        }
        this.scaleUI(this._opts.scaleUI[0], this._opts.scaleUI[1]);
      } else {
        this.scaleUI(576, 1024);
      }
    }

constructor (opts) {
    super(merge(opts, defaults));
  }
  _forceLoad () {