public function getAccessToken($forceRefresh = false)
    {
        $cacheKey = $this->getCacheKey();
        $cached = $this->getCache()->fetch($cacheKey);

        if (empty($cached) || $forceRefresh) {
            $token = $this->getTokenFormApi();

            $this->getCache()->save($cacheKey, $token[$this->tokenSucessKey], $token['expires_in']);

            return $token[$this->tokenSucessKey];
        }

        return $cached;
    }