code: public void submit(String name, Map<String, String> additionalMetadata) {
      if(this.metricContext.isPresent()) {
        Map<String, String> finalMetadata = Maps.newHashMap(this.metadata);
        if(!additionalMetadata.isEmpty()) {
          finalMetadata.putAll(additionalMetadata);
        }
  
        // Timestamp is set by metric context.
        this.metricContext.get().submitEvent(new GobblinTrackingEvent(0l, this.namespace, name, finalMetadata));
      }
    }
docs: Submits the {@link org.apache.gobblin.metrics.GobblinTrackingEvent} to the {@link org.apache.gobblin.metrics.MetricContext}.
  @param name Name of the event.
  @param additionalMetadata Additional metadata to be added to the event.