@Test void metricsIsOK() throws Exception {
    assertThat(get("/metrics").isSuccessful())
      .isTrue();

    // ensure we don't track metrics in prometheus
    assertThat(scrape())
      .doesNotContain("metrics");
  }
Only add tests that do not consider the value of a counter or gauge, as these will flake and so
should only exist in {@link ITZipkinMetricsDirty}.
zipkin-server/src/test/java/zipkin2/server/internal/prometheus/ITZipkinMetrics.java