code: func (t *TimeoutWheel) Stop() {
  	t.lockAllBuckets()
  
  	if t.state == running {
  		t.state = stopping
  		close(t.calloutCh)
  		for i := range t.buckets {
  			t.freeBucketLocked(t.buckets[i])
  		}
  	}
  
  	// unlock so the callouts can finish.
  	t.unlockAllBuckets()
  	<-t.done
  }
docs: // Stop stops tick processing, and deletes any remaining timeouts.