@Test protected void getTraces_returnsEmptyOnNotFound(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    Span span1 = spanBuilder(testSuffix).build(), span2 = spanBuilder(testSuffix).build();
    List<String> traceIds = List.of(span1.traceId(), span2.traceId());

    assertGetTracesReturnsEmpty(traceIds);

    accept(span1, span2);

    assertGetTracesReturns(traceIds, List.of(span1), List.of(span2));

    List<String> shortTraceIds =
      traceIds.stream().map(t -> t.substring(16)).collect(Collectors.toList());
    assertGetTracesReturnsEmpty(shortTraceIds);
  }
Prevents subtle bugs which can result in mixed-length traces from linking.
zipkin-tests/src/main/java/zipkin2/storage/ITTraces.java