public function put(EventInterface $event) {
        $request = $event->getRequest();
        $metadata = json_decode($request->getContent(), true);

        $event->getManager()
            ->trigger('db.metadata.delete')
            ->trigger('db.metadata.update', [
                'metadata' => $metadata,
            ]);

        $model = new Model\Metadata();
        $model->setData($metadata);

        $event->getResponse()->setModel($model);
    }