code: func ThrottledWriter(w io.Writer, bytesPerSec int, maxBurst time.Duration) ThrottlerWriter {
  	return &throttledWriter{
  		wrap:    w,
  		limiter: newRateLimiter(bytesPerSec, maxBurst),
  	}
  }
docs: // ThrottledWriter ensures that writes to `w` never exceeds a specified rate of
  // bytes per second. The `maxBurst` duration changes how often the verification is
  // done. The smaller the value, the less bursty, but also the more overhead there
  // is to the throttling.