fkooman\OAuth\Client\SessionStorage::storeAccessToken PHP Method

    public function storeAccessToken(AccessToken $accessToken)
    {
        if (!isset($_SESSION['php-oauth-client']['access_token'])) {
            $_SESSION['php-oauth-client']['access_token'] = array();
        }
        array_push($_SESSION['php-oauth-client']['access_token'], serialize($accessToken));
        return true;
    }