code: func (typedData *TypedData) HashStruct(primaryType string, data TypedDataMessage) (hexutil.Bytes, error) {
  	encodedData, err := typedData.EncodeData(primaryType, data, 1)
  	if err != nil {
  		return nil, err
  	}
  	return crypto.Keccak256(encodedData), nil
  }
docs: // HashStruct generates a keccak256 hash of the encoding of the provided data