public function transform(EventInterface $event)
{
$params = $event->getArgument('params');
$threshold = !empty($params['threshold']) ? (double) $params['threshold'] : $this->threshold;
try {
$this->imagick->sepiaToneImage($threshold);
$event->getArgument('image')->hasBeenTransformed(true);
} catch (ImagickException $e) {
throw new TransformationException($e->getMessage(), 400, $e);
}
}