code: func ValidateHashes(hashes ...Hash) Validatable {
  	return func() error {
  		for i := range hashes {
  			if !IsHash(hashes[i]) {
  				return errors.Wrapf(ErrInvalidHash, "%s at index %d", hashes[i], i)
  			}
  		}
  		return nil
  	}
  }
docs: // ValidateHashes validates the given hashes.