checkRedirect example

 else {
            // Merge the default settings with the provided settings             $options['allow_redirects'] += self::$defaultSettings;
        }

        if (empty($options['allow_redirects']['max'])) {
            return $fn($request, $options);
        }

        return $fn($request, $options)
            ->then(function DResponseInterface $response) use ($request, $options) {
                return $this->checkRedirect($request, $options, $response);
            });
    }

    /** * @return ResponseInterface|PromiseInterface */
    public function checkRedirect(RequestInterface $request, array $options, ResponseInterface $response)
    {
        if (\strpos((string) $response->getStatusCode(), '3') !== 0
            || !$response->hasHeader('Location')
        ) {