@Test void delegatesSpanConsumer() {
    SpanConsumer spanConsumer = mock(SpanConsumer.class);
    when(delegate.spanConsumer()).thenReturn(spanConsumer);

    assertThat(forwarder.spanConsumer()).isEqualTo(spanConsumer);

    verify(delegate).spanConsumer();
  }
This test is intentionally brittle. It should break if we add new methods on {@link
StorageComponent}!
zipkin/src/test/java/zipkin2/storage/ForwardingStorageComponentTest.java