protected function sdk()
    {
        if (empty($this->oSdk)) {
            $this->oSdk = new \Aws\S3\S3Client([
                'version'     => 'latest',
                'region'      => $this->getRegion(),
                'credentials' => new \Aws\Credentials\Credentials(
                    $this->getSetting('access_key'),
                    $this->getSetting('access_secret')
                ),
            ]);
        }

        return $this->oSdk;
    }