@Test protected void getTraces_lateDuration(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    Span clientSpan = newClientSpan(testSuffix);
    Span missingDuration = clientSpan.toBuilder().duration(0L).build();
    Span lateDuration = Span.newBuilder()
      .traceId(clientSpan.traceId())
      .id(clientSpan.id())
      .timestamp(clientSpan.timestampAsLong())
      .duration(clientSpan.durationAsLong())
      .localEndpoint(clientSpan.localEndpoint())
      .build();
    accept(missingDuration);
    accept(lateDuration);

    assertGetTracesReturnsEmpty(
      requestBuilder().minDuration(clientSpan.durationAsLong() + 1).build());

    assertGetTracesReturns(
      requestBuilder().minDuration(clientSpan.durationAsLong()).build(),
      List.of(lateDuration, missingDuration));
  }
This is unlikely and means instrumentation sends empty spans by mistake.
zipkin-tests/src/main/java/zipkin2/storage/ITSpanStore.java