code: @VisibleForTesting
    static RateLimiter create(SleepingStopwatch stopwatch, double permitsPerSecond) {
      RateLimiter rateLimiter = new SmoothBursty(stopwatch, 1.0 /* maxBurstSeconds */);
      rateLimiter.setRate(permitsPerSecond);
      return rateLimiter;
    }
docs: /*
  TODO(cpovirk): make SleepingStopwatch the last parameter throughout the class so that the
  overloads follow the usual convention: Foo(int), Foo(int, SleepingStopwatch)