code: public static List<FileStatus> listFilesRecursively(FileSystem fs, Path path, PathFilter fileFilter)
        throws IOException {
      return listFilesRecursively(fs, path, fileFilter, false);
    }
docs: Helper method to list out all files under a specified path. The specified {@link PathFilter} is treated as a file
  filter, that is it is only applied to file {@link Path}s.