class CartManager {

    public Long calculateTax() {
        if (mLineItemTax == null) {
            return 0L;
        }

        if (!mCurrency.getCurrencyCode().equals(mLineItemTax.getCurrencyCode())) {
            return null;
        }

        return PaymentUtils.getPriceLong(mLineItemTax.getTotalPrice(), mCurrency);
    }

    public  CartManager();
    public  CartManager(String currencyCode);
    public  CartManager(@NonNull Cart oldCart);
    public  CartManager(@NonNull Cart oldCart, boolean shouldKeepShipping, boolean shouldKeepTax);

}