code: public DirectoryWatcher newWatcher(Path dir, String separator) throws IOException {
      DirectoryWatcher watcher = new DirectoryWatcher(this.watchService, dir, separator);
      addWatcher(watcher);
  
      return watcher;
    }
docs: <p>
  Instantiates a new DirectoryWatcher for the path given.
  </p>
  
  @param dir       the path to watch for events.
  @param separator the file path separator for this watcher
  @return a DirectoryWatcher for this path (and all child paths)
  @throws IOException