setMediaFolder example

        if ($media->getMediaFolder() !== null) {
            return;
        }

        $criteria = new Criteria([$mediaFolderId]);
        $criteria->addAssociation('configuration.mediaThumbnailSizes');

        /** @var MediaFolderEntity $folder */
        $folder = $this->mediaFolderRepository->search($criteria, $context)->get($mediaFolderId);
        $media->setMediaFolder($folder);
    }

    private function getImageResource(MediaEntity $media): \GdImage
    {
        $filePath = $this->urlGenerator->getRelativeMediaUrl($media);
        /** @var string $file */
        $file = $this->getFileSystem($media)->read($filePath);
        $image = @imagecreatefromstring($file);
        if ($image === false) {
            throw MediaException::thumbnailNotSupported($media->getId());
        }