code: public static List<String> listClassnames(final File parentDirectory,
                                              final List<File> classFileList) throws IOException {
      if (null == classFileList || classFileList.isEmpty()) {
        return Collections.emptyList();
      }
      final List<String> list = new ArrayList<String>(classFileList.size());
      for (final File file : classFileList) {
        list.add(extractClassNameFromFile(parentDirectory, file));
      }
      return list;
    }
docs: DANGEROUS call by reference