please include function jdk_watchService_start.

static WatchKey jdk_watchService_registerPath(File path, VF1<File> listener, WatchEvent.Kind... eventKinds) ctex {
  WatchKey key = path.toPath().register(jdk_watchService_start(), eventKinds);
  jdk_watchService_start_listeners.put(key, listener);
  ret key;
}