code: func (b *batch) Replay(w ethdb.Writer) error {
  	for _, keyvalue := range b.writes {
  		if keyvalue.delete {
  			if err := w.Delete(keyvalue.key); err != nil {
  				return err
  			}
  			continue
  		}
  		if err := w.Put(keyvalue.key, keyvalue.value); err != nil {
  			return err
  		}
  	}
  	return nil
  }
docs: // Replay replays the batch contents.