code: public static GobblinMetrics get(final String id, final MetricContext parentContext, final List<Tag<?>> tags) {
      return GOBBLIN_METRICS_REGISTRY.getOrDefault(id, new Callable<GobblinMetrics>() {
        @Override
        public GobblinMetrics call()
            throws Exception {
          return new GobblinMetrics(id, parentContext, tags);
        }
      });
    }
docs: Get a {@link GobblinMetrics} instance with the given ID, parent {@link MetricContext},
  and list of {@link Tag}s.
  
  @param id the given {@link GobblinMetrics} ID
  @param parentContext the given parent {@link MetricContext}
  @param tags the given list of {@link Tag}s
  @return a {@link GobblinMetrics} instance