if err := enc.Encode(prevResult); err != nil {
					return
				}
			} else {
				// first result is not yet obtained, keep writing
				// empty entry to prevent client from disconnecting.
				if err := enc.Encode(madmin.SpeedTestResult{}); err != nil {
					return
				}
			}
			w.(http.Flusher).Flush()
		case result, ok := <-ch:
			if !ok {
				return
			}