code: func (b Bucket) Delete(k [][]byte) error {
  	return b.OpenBucket(k[:len(k)-1], func(b Bucket) error {
  		return errorsp.WithStacks(b.Bucket.Delete(k[len(k)-1]))
  	})
  }
docs: // Delete removes a key from the bucket. If the key does not exist then
  // nothing is done and a nil error is returned. Returns an error if the
  // bucket was created from a read-only transaction.