code: private Map<String, String> buildEventMap() {
  
      Map<String, String> eventMetadataMap = Maps.newHashMap();
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.DATASET_URN_KEY), datasetUrn);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.PARTITION_KEY), partition);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.ORIGIN_TS_IN_MILLI_SECS_KEY), originTimestamp);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.UPSTREAM_TS_IN_MILLI_SECS_KEY), upstreamTimestamp);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.COMPLETENESS_PERCENTAGE_KEY), completenessPercentage);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.RECORD_COUNT_KEY), recordCount);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.PREVIOUS_PUBLISH_TS_IN_MILLI_SECS_KEY), previousPublishTimestamp);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.DEDUPE_STATUS_KEY), dedupeStatus);
      eventMetadataMap.put(withoutPropertiesPrefix(SlaEventKeys.IS_FIRST_PUBLISH), isFirstPublish);
  
      if (additionalMetadata != null) {
        eventMetadataMap.putAll(additionalMetadata);
      }
      return Maps.newHashMap(Maps.filterValues(eventMetadataMap, NOT_NULL_OR_EMPTY_PREDICATE));
    }
docs: Builds an EventMetadata {@link Map} from the {@link #SlaEventSubmitter}. The method filters out metadata by
  applying {@link #NOT_NULL_OR_EMPTY_PREDICATE}