private String getAsString(String path) throws IOException {
    Response response = get(path);
    assertThat(response.isSuccessful())
      .withFailMessage(response.toString())
      .isTrue();
    return response.body().string();
  }
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