code: func notifyBlockers(blockers []*blocker, count int) (newBlockers []*blocker) {
  	for _, b := range blockers {
  		if b.count == count {
  			close(b.ch)
  		} else {
  			newBlockers = append(newBlockers, b)
  		}
  	}
  	return
  }
docs: // notifyBlockers notifies all the blockers waiting until the
  // given number of sleepers are waiting on the fakeClock. It
  // returns an updated slice of blockers (i.e. those still waiting)