code: func PutTaskStatus(tx *bolt.Tx, id string, status *api.TaskStatus) error {
  	return withCreateTaskBucketIfNotExists(tx, id, func(bkt *bolt.Bucket) error {
  		p, err := proto.Marshal(status)
  		if err != nil {
  			return err
  		}
  		return bkt.Put(bucketKeyStatus, p)
  	})
  }
docs: // PutTaskStatus updates the status for the task with id.