code: public void submit(Map<String, String> additionalMetadata) throws IOException {
  
      if (this.submitted) {
        throw new IOException("MultiTimingEvent has already been submitted.");
      }
      this.submitted = true;
  
      endStage();
  
      Map<String, String> finalMetadata = Maps.newHashMap();
      finalMetadata.putAll(additionalMetadata);
      finalMetadata.put(EventSubmitter.EVENT_TYPE, MULTI_TIMING_EVENT);
      for (Stage timing : this.timings) {
        finalMetadata.put(timing.getName(), Long.toString(timing.getDuration()));
      }
  
      this.submitter.submit(this.name, finalMetadata);
    }
docs: Ends the current stage and submits the event containing the timings of each event.
  @param additionalMetadata additional metadata to include in the event.
  @throws IOException