docs: public SampleTableBox getSampleTableBox() {
          if (sampleTableBox != null) {
              return sampleTableBox;
          }
          MediaBox mdia = getMediaBox();
          if (mdia != null) {
              MediaInformationBox minf = mdia.getMediaInformationBox();
              if (minf != null) {
                  sampleTableBox = minf.getSampleTableBox();
                  return sampleTableBox;
              }
          }
          return null;
  
      }