@Test
public void usesDefaultRegistry() {

    SharedMetricRegistries.add(InstrumentedAppender.DEFAULT_REGISTRY, registry);
    final InstrumentedAppender shared = new InstrumentedAppender();
    shared.start();
    when(event.getLevel()).thenReturn(Level.INFO);
    shared.doAppend(event);
    assertThat(SharedMetricRegistries.names()).contains(InstrumentedAppender.DEFAULT_REGISTRY);
    assertThat(registry.meter(METRIC_NAME_PREFIX + ".info").getCount())
            .isEqualTo(1);
}