void assertQueryReturnsResults(QueryRequest.Builder builder, List<List<Span>> traces)
    throws IOException {
    QueryRequest query = builder.endTs(System.currentTimeMillis()).lookback(DAY).limit(2).build();
    assertThat(inMemoryStorage().getTraces(query).execute())
      .withFailMessage("Expected results from %s. Current traces: %s", query, traces)
      .isNotEmpty();
  }
The {@code toString()} of {@link Component} implementations appear in health check endpoints.
Since these are likely to be exposed in logs and other monitoring tools, care should be taken
to ensure {@code toString()} output is a reasonable length and does not contain sensitive
information.
zipkin-server/src/test/java/zipkin2/server/internal/brave/ITZipkinSelfTracing.java