func appendWrite(bucket base.Bucket, key string, vb int, sequence uint64) error {
	sequenceBytes := getSequenceAsBytes(sequence)
	err := bucket.Append(key, sequenceBytes)
	// TODO: assumes err means it hasn't been created yet
	if err != nil {
		added, err := bucket.AddRaw(key, 0, sequenceBytes)
		if err != nil || added == false {
			log.Printf("AddRaw also failed?! %s:%v", key, err)
		}
	}
	return nil
}