@Get("/api/v2/dependencies")
  @Blocking
  public AggregatedHttpResponse getDependencies(
    @Param("endTs") long endTs,
    @Param("lookback") Optional<Long> lookback) throws IOException {
    Call<List<DependencyLink>> call =
      storage.spanStore().getDependencies(endTs, lookback.orElse(defaultLookback));
    return jsonResponse(DependencyLinkBytesEncoder.JSON_V1.encodeList(call.execute()));
  }
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