code: func (s *StateSyncer) staggerFn(d time.Duration) time.Duration {
  	f := scaleFactor(s.ClusterSize())
  	return libRandomStagger(time.Duration(f) * d)
  }
docs: // staggerFn returns a random duration which depends on the cluster size
  // and a random factor which should provide some timely distribution of
  // cluster wide events. This function should not be called directly
  // but through s.stagger to allow mocking for testing.