@Test protected void oneway_noClient(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    String traceId = newTraceId();

    Endpoint backend = suffixServiceName(TestObjects.BACKEND, testSuffix);
    Endpoint kafka = suffixServiceName(TestObjects.KAFKA, testSuffix);

    List<Span> trace = List.of(
      Span.newBuilder().traceId(traceId).id("10").name("receive")
        .timestamp(TODAY * 1000)
        .kind(Kind.SERVER)
        .localEndpoint(backend)
        .remoteEndpoint(kafka)
        .build(),
      Span.newBuilder().traceId(traceId).parentId("10").id("11").name("process")
        .timestamp((TODAY + 25) * 1000L).duration(325L * 1000L)
        .localEndpoint(backend).build()
    );

    processDependencies(trace);

    assertThat(store().getDependencies(endTs(trace), DAY).execute()).containsOnly(
      DependencyLink.newBuilder()
        .parent(kafka.serviceName())
        .child(backend.serviceName())
        .callCount(1)
        .build()
    );
  }
Async span starts from an uninstrumented source.
zipkin-tests/src/main/java/zipkin2/storage/ITDependencies.java