I'm trying to get a list of objects from AWS using the S3fsService from the [S3 File System module](https://www.drupal.org/project/s3fs) from within a `hook_cron()` implementation. The following code works:

    // Fetch list of files in S3.
    $config = \Drupal::config('s3fs.settings')->get();
    $s3 = \Drupal\s3fs\S3fsService::getAmazonS3Client($config);
    $iterator_args = ['Bucket' => $config['bucket']];
    $iterator = $s3->getIterator('ListObjectVersions', $iterator_args);

…but I'm getting a message saying `Deprecated function: Non-static method Drupal\s3fs\S3fsService::getAmazonS3Client() should not be called statically…`.

How should I be calling it differently?

Thanks!