docs: @Get("/metrics")
    @ProducesJson
    public ObjectNode fetchMetricsFromMicrometer() {
      ObjectNode metricsJson = factory.objectNode();
      // Get the Zipkin Custom meters for constructing the Metrics endpoint
      for (Meter meter : meterRegistry.getMeters()) {
        String name = meter.getId().getName();
        if (!name.startsWith("zipkin_collector")) continue;
        String transport = meter.getId().getTag("transport");
        if (transport == null) continue;
        switch (meter.getId().getType()) {
          case COUNTER:
            metricsJson.put("counter." + name + "." + transport,
              ((Counter) meter).count());
            continue;
          case GAUGE:
            metricsJson.put("gauge." + name + "." + transport,
              ((Gauge) meter).value());
        }
      }
      return metricsJson;
    }