copyStreams example

    public function fetchRequestData(Request $request, string $fileName): MediaFile
    {
        $extension = $this->getExtensionFromRequest($request);
        $expectedLength = (int) $request->headers->get('content-length');

        $inputStream = $request->getContent(true);
        $destStream = $this->openDestinationStream($fileName);

        try {
            $bytesWritten = $this->copyStreams($inputStream, $destStream, 0);
        } finally {
            fclose($inputStream);
            fclose($destStream);
        }

        if ($expectedLength !== $bytesWritten) {
            throw MediaException::invalidContentLength();
        }

        return new MediaFile(
            $fileName,