@Get("/api/v2/autocompleteKeys")
  @Blocking
  public AggregatedHttpResponse getAutocompleteKeys(ServiceRequestContext ctx) {
    return maybeCacheNames(true, autocompleteKeys, ctx.alloc());
  }
The Cache-Control max-age (seconds) for /api/v2/services /api/v2/remoteServices and
/api/v2/spans
zipkin-server/src/main/java/zipkin2/server/internal/ZipkinQueryApiV2.java