code: func Until(f func(), period time.Duration, stopCh <-chan struct{}) {
  	JitterUntil(f, period, 0.0, true, stopCh)
  }
docs: // Until loops until stop channel is closed, running f every period.
  //
  // Until is syntactic sugar on top of JitterUntil with zero jitter factor and
  // with sliding = true (which means the timer for period starts after the f
  // completes).