static File javaxDownloadsDir_dir; // can be set to work on different base dir

static File javaxDownloadsDir() {
  ret javaxDownloadsDir_dir != null ? javaxDownloadsDir_dir : new File(userHome(), "JavaX-Downloads");
}

static File javaxDownloadsDir(S... subs) {
  ret newFile(javaxDownloadsDir(), subs);
}