code: func globalRandRead(b []byte) {
  	pos := 0
  	val := 0
  	for n := 0; n < len(b); n++ {
  		if pos == 0 {
  			val = rand.Int()
  			pos = 7
  		}
  		b[n] = byte(val)
  		val >>= 8
  		pos--
  	}
  }
docs: // package rand provides a Read function in Go 1.6 and later, but
  // we can't use it yet because we still support Go 1.5.