code: func (h *DBHeader) ValidateHmacSha256(hmacKey []byte, hash [32]byte) error {
  	hmacSha := h.GetHmacSha256(hmacKey)
  	if !reflect.DeepEqual(hmacSha, hash) {
  		return errors.New("HMAC-Sha256 of header mismatching")
  	}
  	return nil
  }
docs: // ValidateHmacSha256 validates the given hash with the HMAC-Sha256 of the header