public function createEvent($testKey, $variantKey, $eventKey, $participantId, $metadata = null)
{
$value = isset($metadata['value']) ? $metadata['value'] : null;
$event = new Event();
$event->setTestKey($testKey);
$event->setVariantKey($variantKey);
$event->setEventKey($eventKey);
$event->setParticipantId($participantId);
$event->setMetadata($metadata);
$event->setValue($value);
$event->setTimeCreated(new \DateTime());
$this->entityManager->persist($event);
$this->entityManager->flush();
}
