The following example uses the Amazon S3 `Downloader` to download a file. Using `Downloader` is similar to the [s3.GetObject](https://pkg.go.dev/github.com/aws/aws-sdk-go-v2/service/s3#Client.GetObject) operation.
The `downloadFile` parameter is an `io.WriterAt` type. The `WriterAt` interface enables the `Downloader` to write multiple parts of the file in parallel.