code: public List<Metric> poll(MetricFilter filter, boolean reset) {
      refreshMonitorCache(filter);
      List<Monitor<?>> monitors = cachedMonitors.get();
      List<Metric> metrics = new ArrayList<>(monitors.size());
      for (Monitor<?> monitor : monitors) {
        Object v = getValue(monitor);
        if (v != null) {
          metrics.add(new Metric(monitor.getConfig(), clock.now(), v));
        }
      }
      return metrics;
    }
docs: {@inheritDoc}