public double calculateTax(Goods goods) {
        double tax = 0.0;
        if(!goods.getIsExemption()){
            tax = goods.getPrice() * TaxRate.COMMON;
        }
        if(goods.getIsImport()){
            tax += goods.getPrice() * TaxRate.IMPORT;
        }
        tax = (int) ((tax + 0.04)/5.0 * 100.0) / 100.0 * 5;
        BigDecimal bigDecimal = new BigDecimal(tax);
        bigDecimal =  bigDecimal.setScale(2, BigDecimal.ROUND_HALF_UP);
        return bigDecimal.doubleValue();
    }