code: func (tx Tx) CreateBucketIfNotExists(folders [][]byte) (Bucket, error) {
  	b, err := tx.Tx.CreateBucketIfNotExists(folders[0])
  	if err != nil {
  		return Bucket{}, nil
  	}
  	if len(folders) == 1 {
  		return Bucket{b}, nil
  	}
  	return Bucket{b}.CreateBucketIfNotExists(folders[1:])
  }
docs: // CreateBucketIfNotExists creates a new bucket if it doesn't already
  // exist. Returns an error if the bucket name is blank, or if the bucket
  // name is too long. The bucket instance is only valid for the lifetime of
  // the transaction.