@Test void messagingSpansDontLinkWithoutBroker_consumer() {
    List<Span> trace = List.of(
      span("a", null, "a", Kind.PRODUCER, "producer", null, false),
      span("a", "a", "b", Kind.CONSUMER, "consumer", "kafka", false)
    );

    assertThat(new DependencyLinker().putTrace(trace).link()).containsOnly(
      DependencyLink.newBuilder().parent("kafka").child("consumer").callCount(1L).build()
    );
  }
This test shows that if a parent ID is stored late (ex because it wasn't propagated), the span
can resolve even if the client side is never sent
zipkin/src/test/java/zipkin2/internal/DependencyLinkerTest.java