ApiPlatform\Core\EventListener\ReadListener::getItemData PHP Method

    private function getItemData(Request $request, array $attributes)
    {
        $id = $request->attributes->get('id');
        $data = $this->itemDataProvider->getItem($attributes['resource_class'], $id, $attributes['item_operation_name']);
        if (null === $data) {
            throw new NotFoundHttpException('Not Found');
        }
        return $data;
    }