### Question:
PriceUtils { public static MonetaryAmount convertGrossToNetPrice(final MonetaryAmount grossAmount, final double taxRate) { return grossAmount.divide(1 + taxRate); } private  PriceUtils(); static MonetaryAmount zeroAmount(final CurrencyUnit currency); static MonetaryAmount calculateAppliedTaxes(final TaxedItemPrice taxedPrice); static MonetaryAmount calculateGrossPrice(final MonetaryAmount amount, final TaxRate taxRate); static MonetaryAmount calculateNetPrice(final MonetaryAmount amount, final TaxRate taxRate); static MonetaryAmount convertNetToGrossPrice(final MonetaryAmount netAmount, final double taxRate); static MonetaryAmount convertGrossToNetPrice(final MonetaryAmount grossAmount, final double taxRate);  }### Answer:
@Test public void convertsToNet() throws Exception { final MonetaryAmount grossAmount = monetaryAmountOf(119); final double taxRate = 0.19; assertThat(convertGrossToNetPrice(grossAmount, taxRate)).isEqualTo(monetaryAmountOf(100)); }