@Override
    public Double getValue() {
        return getRatio().getValue();
    }
@Test
    public void handlesNaNDenominators() {
        final RatioGauge nan = new RatioGauge() {
            @Override
            protected Ratio getRatio() {
                return Ratio.of(10, Double.NaN);
            }
        };

        assertThat(nan.getValue())
                .isNaN();
    }