我可以使用Go SDK 2从AWS S3获取前X个字节吗

Question

I would like to get the first X Bytes from a very large CSV file. I basically just want to get the first two rows so I get the column names and an example of the data in each. However, I know that this isn't going to be possible so I would like to just download enough bytes to reasonably have enough data to be able to look at the first two rows. I am therefore trying to download the first 64kB.

I am trying to do this using the s3 manager ( https://github.com/aws/aws-sdk-go/blob/master/service/s3/s3manager/download.go )

I tried using something like :

downloader := s3manager.NewDownloaderWithClient(svc, func(d *s3manager.Downloader) {
    d.PartSize = 1024 * 64
    d.Concurrency = 1
})

` This hangs though. I'd imagine I am just telling it to download the file with a small part size and it stops there and never returns anything.

Can anybody cleverer than me tell me how I can download just the first X bytes of an S3 file in go? Thanks!