@Test protected void getTraces_spanName_mixedTraceIdLength(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    Span clientSpan = newClientSpan(testSuffix);

    // add a trace with the same trace ID truncated to 64 bits, except the span name.
    accept(clientSpan.toBuilder()
      .traceId(clientSpan.traceId().substring(16))
      .name("bar")
      .build());

    getTraces_spanName(clientSpan);
  }
This is unlikely and means instrumentation sends empty spans by mistake.
zipkin-tests/src/main/java/zipkin2/storage/ITSpanStore.java