Function dataflow::source::s3::download_object

async fn download_object(
    tx: &Sender<Result<InternalMessage, S3Error>>, 
    activator: &SyncActivator, 
    client: &S3Client, 
    bucket: &str, 
    key: &str, 
    compression: Compression, 
    source_id: &str
) -> Result<DownloadMetricUpdate, DownloadError>