public function getCollectionsByStorage(StorageInterface $storage)
    {
        $this->initialize();

        $collections = [];
        foreach ($this->collections as $collectionName => $collection) {
            /** @var CollectionInterface $collection */
            if ($collection->getStorage() === $storage) {
                $collections[$collectionName] = $collection;
            }
        }
        return $collections;
    }