@Test protected void getTagsAndValues(TestInfo testInfo) throws Exception {
    String testSuffix = testSuffix(testInfo);
    for (int i = 0; i < 2; i++) {
      accept(spanBuilder(testSuffix)
        .putTag("http.method", "GET")
        .putTag("http.host", "host1")
        .build());
    }

    assertThat(storage.autocompleteTags().getKeys().execute())
      .containsOnlyOnce("http.host");

    assertThat(storage.autocompleteTags().getValues("http.host").execute())
      .containsOnlyOnce("host1");
  }
Base test for when {@link StorageComponent.Builder#autocompleteKeys(List)} has values.

<p>Subtypes should create a connection to a real backend, even if that backend is in-process.
zipkin-tests/src/main/java/zipkin2/storage/ITAutocompleteTags.java