type Config struct {
	Bucket            string
	Region            string
	Prefix            string
	ManifestsPrefix   string
	BlobsPrefix       string
	Names             []string
	TouchRefresh      time.Duration
	EndpointURL       string
	AccessKeyID       string
	SecretAccessKey   string
	SessionToken      string
	UsePathStyle      bool
	UploadParallelism int
}

type ReaderAtCloser interface {
	io.ReaderAt
	io.Closer
}