public function getActiveSessions()
    {
        $activeSessions = [];
        foreach ($this->metaDataCache->getByTag('session') as $sessionIdentifier => $sessionInfo) {
            $session = new Session($sessionIdentifier, $sessionInfo['storageIdentifier'], $sessionInfo['lastActivityTimestamp'], $sessionInfo['tags']);
            $activeSessions[] = $session;
        }
        return $activeSessions;
    }