List<Span> acceptMixedTrace(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    List<Span> trace = newTrace(testSuffix);
    String downgraded = trace.get(0).traceId().substring(16);
    // iterate after the outbound client span, emulating a server that downgraded
    for (int i = 2; i < trace.size(); i++) {
      trace.set(i, trace.get(i).toBuilder().traceId(downgraded).build());
    }
    Collections.reverse(trace);
    accept(trace.toArray(new Span[0]));
    return sortTrace(trace);
  }
Ensures we can still lookup fully 128-bit traces when strict trace ID id disabled
zipkin-tests/src/main/java/zipkin2/storage/ITStrictTraceIdFalse.java