code: func CpuBench(iterations int, duration time.Duration, useWeakHash bool) float64 {
  	dataSize := 16 * protocol.MinBlockSize
  	bs := make([]byte, dataSize)
  	rand.Reader.Read(bs)
  
  	var perf float64
  	for i := 0; i < iterations; i++ {
  		if v := cpuBenchOnce(duration, useWeakHash, bs); v > perf {
  			perf = v
  		}
  	}
  	blocksResult = nil
  	return perf
  }
docs: // CpuBench returns CPU performance as a measure of single threaded SHA-256 MiB/s