createSink example

 catch (\Exception $e) {
            return P\Create::rejectionFor(
                new RequestException('An error was encountered while creating the response', $request, null, $e)
            );
        }

        [$stream, $headers] = $this->checkDecode($options, $headers, $stream);
        $stream = Psr7\Utils::streamFor($stream);
        $sink = $stream;

        if (\strcasecmp('HEAD', $request->getMethod())) {
            $sink = $this->createSink($stream, $options);
        }

        try {
            $response = new Psr7\Response($status, $headers, $sink, $ver, $reason);
        } catch (\Exception $e) {
            return P\Create::rejectionFor(
                new RequestException('An error was encountered while creating the response', $request, null, $e)
            );
        }

        if (isset($options['on_headers'])) {