@Override
    public Double getValue() {
        return getRatio().getValue();
    }
@Test
    public void calculatesTheRatioOfTheNumeratorToTheDenominator() throws Exception {
        final RatioGauge regular = new RatioGauge() {
            @Override
            protected Ratio getRatio() {
                return RatioGauge.Ratio.of(2, 4);
            }
        };

        assertThat(regular.getValue())
                .isEqualTo(0.5);
    }