// gzip the response and throttle the handler via `maxClients`. Each of these
// can be disabled via the corresponding `s3HFlag`.
//
// CAUTION: for requests involving large req/resp bodies ensure to pass the
// `traceHdrsS3HFlag`, otherwise both headers and body will be traced, causing
// high memory usage!
func s3APIMiddleware(f http.HandlerFunc, flags ...s3HFlag) http.HandlerFunc {