docs: public long[] getTrackNumbers() {
  
          List<TrackBox> trackBoxes = this.getBoxes(TrackBox.class);
          long[] trackNumbers = new long[trackBoxes.size()];
          for (int trackCounter = 0; trackCounter < trackBoxes.size(); trackCounter++) {
              trackNumbers[trackCounter] = trackBoxes.get(trackCounter).getTrackHeaderBox().getTrackId();
          }
          return trackNumbers;
      }