@Test
  public void should_exchange_100_RMB_to_16_67_AUD() {
    ExchangePage exchangePage = navigator.toExchangePage();
    ExchangeResultPage resultPage = exchangePage.exchange(Currency.RMB, Currency.AUD, 100);

    double toAmount = resultPage.getToAmount();
    assertThat(toAmount, is(16.67));
  }
  @Test
  public void should_exchange_1_AUD_to_6_RMB() {
    ExchangePage exchangePage = navigator.toExchangePage();
    ExchangeResultPage resultPage = exchangePage.exchange(Currency.AUD, Currency.RMB, 1);

    double toAmount = resultPage.getToAmount();
    assertThat(toAmount, is(6.0));
  }