fkooman / php-oauth2-client

        if ($accessToken->isExpired($this->dateTime)) {

            $this->logger->info(sprintf('access_token for user "%s" with scope "%s" expired', $this->userId, $requestScope));

            // access_token is expired, try to refresh it

            if (is_null($accessToken->getRefreshToken())) {

                $this->logger->info(sprintf('no refresh_token available in this access_token for user "%s" with scope "%s", deleting it', $this->userId, $requestScope));

                // we do not have a refresh_token, delete this access token, it

                // is useless now...

                $this->tokenStorage->deleteAccessToken($this->userId, $accessToken);

                return false;

            }

            $this->logger->info(sprintf('using refresh_token to obtain new access_token for user "%s" with scope "%s"', $this->userId, $requestScope));

        $request->setHeader('Authorization', sprintf('Bearer %s', $accessToken->getToken()));

        $response = $this->httpClient->send($request);

        if (401 === $response->getStatusCode()) {

            $this->logger->info(sprintf('deleting access_token for user "%s" with scope "%s" that was supposed to work, but did not, possibly revoked by user', $this->userId, $requestScope));

            // this indicates an invalid access_token

            $this->tokenStorage->deleteAccessToken($this->userId, $accessToken);

            return false;

        }

        $this->logger->info(sprintf('access_token for use "%s" with scope "%s" successfully used', $this->userId, $requestScope));