/**
  * @return string
  */
 public static function getS3Url()
 {
     global $CFG;
     if (!isset($CFG->aws_s3_bucket)) {
         return '';
     }
     if (isset($CFG->aws_cloudfront_url)) {
         return 'https://' . $CFG->aws_cloudfront_url . S3Util::getPrefix();
     }
     return 'https://' . $CFG->aws_s3_bucket . '.s3.amazonaws.com' . S3Util::getPrefix();
 }
 /**
  * @param $file_contenthash
  * @param $file_statusamazon
  * @return string
  */
 public function getTokenUrl($file_contenthash, $file_statusamazon)
 {
     $fileRelativeLocation = substr($this->path_from_hash($file_contenthash), 1);
     if (!class_exists('S3Util')) {
         require_once __DIR__ . '/S3Util.php';
     }
     $file = S3Util::getPrefix() . $fileRelativeLocation;
     if ($file_statusamazon == 'public') {
         return S3Util::getS3Url() . $fileRelativeLocation;
     }
     return $this->client->getObjectUrl($this->bucket_name, $file, '+5 minutes');
 }