code: func (b Bucket) CreateBucketIfNotExists(folders [][]byte) (Bucket, error) {
  	bb := b.Bucket
  	for _, fld := range folders {
  		var err error
  		if bb, err = bb.CreateBucketIfNotExists(fld); err != nil {
  			return Bucket{}, errorsp.WithStacks(err)
  		}
  	}
  	return Bucket{bb}, nil
  }
docs: // CreateBucketIfNotExists creates a new bucket if it doesn't already
  // exist and returns a reference to it. 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.