@Override
    public MetricType getType() {
        return MetricType.GAUGE_NUMBER;
    }
@Test
    public void set() {
        NumberGauge gauge = new NumberGauge("bar");
        assertThat(gauge.getValue()).isNull();
        gauge.set(123l);
        assertThat(gauge.getValue()).isEqualTo(123l);
        assertThat(gauge.getType()).isEqualTo(MetricType.GAUGE_NUMBER);
    }