@Override
    public int hashCode() {
        int result = houseNumber;
        result = 31 * result + (street != null ? street.hashCode() : 0);
        result = 31 * result + (city != null ? city.hashCode() : 0);
        result = 31 * result + (postcode != null ? postcode.hashCode() : 0);
        return result;
    }