example.ts

return this.repository.getEventById(msg.getReferenceIdentifier()).then((eventO: m.Option<domain.core.Event>) => {

  if (!eventO.isDefined) {
    this.logger.error("%s - Could not find event.", event.id)
    return Promise.resolve(new message.ImageIntelligenceRequeueRequest(event, false))
  }

  var event = eventO.get();

  // If it does contain a person, handle person
  if (msg.doesEventContainPerson) {
    this.logger.info("%s - Received callback from ImageIntelligence with persons detected.", event.id)
    return this.handlePersonFoundResponse(msg, event).then(function() {
      return Promise.resolve(new message.ImageIntelligenceRequeueRequest(event, false))
    })
  }

  // If it does not contain a person, and event has not ended, requeue for further analysis.
  if (!msg.doesEventContainPerson() && !event.hasEnded) {
    this.logger.info("%s - Received callback from ImageIntelligence with no persons detected but event is not finished. Requeuing", event.id)
    return Promise.resolve(new message.ImageIntelligenceRequeueRequest(event, true))
  }

  // If it does not contain a person, and event has ended, don't requeue
  this.logger.info("%s - Received callback from ImageIntelligence with no persons detected, and event has finished. Not requeuing", event.id)
  return Promise.resolve(new message.ImageIntelligenceRequeueRequest(event, false))
})