code: func (t *timer) checkExpiration() bool {
  	// Transition to fully disabled state if we're just consuming an
  	// orphaned timer.
  	if t.state == timerStateOrphaned {
  		t.state = timerStateDisabled
  		return false
  	}
  
  	// The timer is enabled, but it may have expired early. Check if that's
  	// the case, and if so, reset the runtime timer to the correct time.
  	now := time.Now()
  	if now.Before(t.target) {
  		t.runtimeTarget = t.target
  		t.timer.Reset(t.target.Sub(now))
  		return false
  	}
  
  	// The timer has actually expired, disable it for now and inform the
  	// caller.
  	t.state = timerStateDisabled
  	return true
  }
docs: // checkExpiration checks if the given timer has actually expired, it should be
  // called whenever a sleeper wakes up due to the waker being asserted, and is
  // used to check if it's a supurious wake (due to a previously orphaned timer)
  // or a legitimate one.