code: public List<ISO9660File> getFiles() {
          List<ISO9660File> files = new ArrayList<ISO9660File>();
  
          if (publisher instanceof ISO9660File) {
              files.add((ISO9660File) publisher);
          }
          if (dataPreparer instanceof ISO9660File) {
              files.add((ISO9660File) dataPreparer);
          }
          if (app instanceof ISO9660File) {
              files.add((ISO9660File) app);
          }
  
          files.add(abstractFile);
          files.add(bibFile);
          files.add(copyrightFile);
  
          return files;
      }
docs: Returns active metadata files<br> Possibly including Publisher, Data Preparer and Application Identifier as well
  as Abstract, Bibliographic and Copyright File
  
  @return Vector of all active metadata files