@Test protected void getSpanNames_serviceNameGoesLowercase(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    Span span = spanBuilder(testSuffix).build();
    accept(span);

    String uppercase = span.localServiceName().toUpperCase(Locale.ROOT);
    assertThat(names().getSpanNames(uppercase).execute())
      .containsExactly(span.name());
  }
Ensures the span name index returns distinct results
zipkin-tests/src/main/java/zipkin2/storage/ITServiceAndSpanNames.java