public function transform(EventInterface $event)
{
$params = $event->getArgument('params');
if (empty($params['level'])) {
throw new TransformationException('Missing required parameter: level', 400);
}
$this->level = (int) $params['level'];
if ($this->level < 0 || $this->level > 100) {
throw new TransformationException('level must be between 0 and 100', 400);
}
}