code: func (tx *transaction) notifyActiveIters() {
  	tx.activeIterLock.RLock()
  	for _, iter := range tx.activeIters {
  		iter.ForceReseek()
  	}
  	tx.activeIterLock.RUnlock()
  }
docs: // notifyActiveIters notifies all of the active iterators for the pending keys
  // treap that it has been updated.