code: func DumpStats(sr *statspkg.Receiver, destFile string) {
  	sr.Lock()
  	defer sr.Unlock()
  
  	f, err := os.Create(destFile)
  	if err != nil {
  		log.Fatal(err)
  	}
  
  	var sum int64
  	for _, size := range sr.Have {
  		fmt.Fprintf(f, "%d\n", size)
  	}
  	fmt.Printf("In-memory blob stats: %d blobs, %d bytes\n", len(sr.Have), sum)
  
  	err = f.Close()
  	if err != nil {
  		log.Fatal(err)
  	}
  }
docs: // DumpStats creates the destFile and writes a line per received blob,
  // with its blob size.