code: function recordOrderInGoogleAnalytics( cart, orderId ) {
  	if ( ! isAdTrackingAllowed() ) {
  		debug( 'recordOrderInGoogleAnalytics: skipping as ad tracking is disallowed' );
  		return;
  	}
  
  	const transaction = {
  		id: orderId,
  		affiliation: 'WordPress.com',
  		revenue: cart.total_cost,
  		currency: cart.currency,
  	};
  	debug( 'recordOrderInGoogleAnalytics: ga ecommerce add transaction', transaction );
  	window.ga( 'ecommerce:addTransaction', transaction );
  }
docs: Records an order in Google Analytics
  
  @see https://developers.google.com/analytics/devguides/collection/analyticsjs/ecommerce
  
  @param {Object} cart - cart as `CartValue` object
  @param {Number} orderId - the order id
  @returns {void}