You don't like warp multipart ?

warp multipart doesn't allow to benchmark multipart upload itself. It mostly benchmarks download and only uploads to a single multipart upload id.

Proposed solution is aimed to benchmark uploading of multiple multipart objects concurrently. It periodically creates new multipart uploads and concurrently uploads parts.

So proposed warp multipart-upload benchmarks a different scenario from warp multipart.

Just updated PR. I renamed both multipart_upload.go files to multipart_put.go as well.
Please take a look.

Updated it once again.

2 minor lint issues. We can merge if those get resolved.

Just resolved it.