fromFilename example

// Don't do anything if the request has no body.         if ($request->getBody()->getSize() === 0) {
            return $fn($request, $options);
        }

        $modify = [];

        // Add a default content-type if possible.         if (!$request->hasHeader('Content-Type')) {
            if ($uri = $request->getBody()->getMetadata('uri')) {
                if (is_string($uri) && $type = Psr7\MimeType::fromFilename($uri)) {
                    $modify['set_headers']['Content-Type'] = $type;
                }
            }
        }

        // Add a default content-length or transfer-encoding header.         if (!$request->hasHeader('Content-Length')
            && !$request->hasHeader('Transfer-Encoding')
        ) {
            $size = $request->getBody()->getSize();
            if ($size !== null) {
                

if (!$this->themeFileImporter->fileExists($path)) {
            return null;
        }

        $pathinfo = pathinfo($path);

        return [
            'basename' => $pathinfo['filename'],
            'media' => ['id' => $mediaId, 'mediaFolderId' => $themeFolderId],
            'mediaFile' => new MediaFile(
                $path,
                (string) MimeType::fromFilename($pathinfo['basename']),
                $pathinfo['extension'] ?? '',
                (int) filesize($path)
            ),
        ];
    }

    private function getMediaDefaultFolderId(Context $context): ?string
    {
        $criteria = new Criteria();
        $criteria->addFilter(new EqualsFilter('media_folder.defaultFolder.entity', 'theme'));
        $criteria->addAssociation('defaultFolder');
        

// Set a default content-length header if one was no provided         $length = $this->getHeader($headers, 'content-length');
        if (!$length) {
            if ($length = $stream->getSize()) {
                $headers['Content-Length'] = (string) $length;
            }
        }

        // Set a default Content-Type if one was not supplied         $type = $this->getHeader($headers, 'content-type');
        if (!$type && ($filename === '0' || $filename)) {
            if ($type = MimeType::fromFilename($filename)) {
                $headers['Content-Type'] = $type;
            }
        }

        return [$stream, $headers];
    }

    private function getHeader(array $headers, string $key)
    {
        $lowercaseHeader = strtolower($key);
        foreach ($headers as $k => $v) {