Prepare the A/B testing to be sent instantly or when it is scheduled.
In the sending object we can indicate the sending date (scheduleAt). If it is the
first time we send the A/B testing, we must pass the parameter total, in which we indicate the total number of devices that will receive the A/B testing, divided equally between the different campaigns that compose it (can not be less than number of campaigns). If we already send the A/B testing and the winning campaign is going to be sent we must pass the parameter campaignSelected to which we will pass the id of the selected campaign for the final sending