code: func (q *Quantity) Unmarshal(data []byte) error {
  	p := QuantityProto{}
  	if err := p.Unmarshal(data); err != nil {
  		return err
  	}
  	q.Format = p.Format
  	b := big.NewInt(0)
  	b.SetBytes(p.Bigint)
  	q.Amount = inf.NewDecBig(b, inf.Scale(p.Scale))
  	return nil
  }
docs: // Reset implements the protobuf marshalling interface.