@Test
public void accessingACustomTimerRegistersAndReusesIt() {

    final MetricRegistry.MetricSupplier<Timer> supplier = () -> timer;
    final Timer timer1 = registry.timer("thing", supplier);
    final Timer timer2 = registry.timer("thing", supplier);
    assertThat(timer1)
            .isSameAs(timer2);
    verify(listener).onTimerAdded("thing", timer1);
}