code: @Override
    public boolean accept(File file) {
      if (file.isDirectory()) {
        return recursively;
      } else if (extension == null) {
        return true;
      } else {
        return file.getName().endsWith(extension);
      }
    }
docs: Checks whether a file satisfies the selection filter.
  
  @param file The file
  @return true if the file is acceptable