static L<File> filesEndingWith(File dir, S suffix) {
  ret listFilesWithSuffix(dir, suffix);
}

static L<File> filesEndingWith(L<File> l, S suffix) {
  new L<File> out;
  for (File f : unnull(l))
    if (!f.isDirectory() && (empty(suffix) || endsWithIgnoreCase(f.getName(), suffix)))
      out.add(f);
  ret out;
}

static L<File> filesEndingWith(S suffix, File dir) {
  ret filesEndingWith(dir, suffix);
}