/** Register the given directory with the WatchService */
 private void register(Path dir) throws IOException {
   WatchKey key = dir.register(watcher, ENTRY_CREATE, ENTRY_DELETE, ENTRY_MODIFY);
   if (trace) {
     Path prev = keys.get(key);
     if (prev == null) {
       System.out.format("register: %s\n", dir);
     } else {
       if (!dir.equals(prev)) {
         System.out.format("update: %s -> %s\n", prev, dir);
       }
     }
   }
   keys.put(key, dir);
 }
  // void processEvents() {
  public void run() {
    System.out.println("WatchDir Thread INFO: priority=" + Thread.currentThread().getPriority());
    for (; ; ) {
      // wait for key to be signalled
      System.out.println("WatchDir INFO: restarting loop...acquiring new key");
      WatchKey key;
      try {
        key = watcher.take();
      } catch (InterruptedException x) {
        return;
      }

      Path dir = keys.get(key);
      if (dir == null) {
        System.err.println("WatchKey not recognized!!");
        continue;
      }

      for (WatchEvent<?> event : key.pollEvents()) {
        WatchEvent.Kind kind = event.kind();
        // TBD - provide example of how OVERFLOW event is handled
        if (kind == OVERFLOW) {
          System.out.println("Encountered OVERFLOW Event - " + event);
          continue;
        }

        // Context for directory entry event is the file name of entry
        WatchEvent<Path> ev = cast(event);
        Path name = ev.context();
        Path child = dir.resolve(name);

        // print out event
        System.out.format("[WatchDir] %s: %s\n", event.kind().name(), child);

        // if directory is created, and watching recursively, then
        // register it and its sub-directories
        if (recursive && (kind == ENTRY_CREATE)) {
          try {
            if (Files.isDirectory(child, NOFOLLOW_LINKS)) {
              registerAll(child);
            }
          } catch (IOException x) {
            // ignore to keep sample readbale
          }
        }

        long t = System.currentTimeMillis();
        if (!Folder.dontWatch.contains(Folder.getInternalPath(child))) {
          Thread.currentThread().setPriority(Thread.NORM_PRIORITY);
          System.out.println(
              "WatchDir#"
                  + key
                  + " INFO: path="
                  + child
                  + ", internal="
                  + Folder.getInternalPath(child)
                  + " is NOT in don't watch list. Forwarding it to other peers. @"
                  + Main.timeToString(t)); // DEBUG
          forwardToItopic(kind, child);
        } else {
          Thread.currentThread().setPriority(Thread.MIN_PRIORITY);
          System.out.println(
              "WatchDir#"
                  + key
                  + " INFO: path="
                  + child
                  + ", internal="
                  + Folder.getInternalPath(child)
                  + " IS in the don't watch list. NOT forwarding. @"
                  + Main.timeToString(t)); // DEBUG
          // try{
          //     Thread.sleep(minDelayBtwnWatchEvents);
          // } catch(InterruptedException ex) {
          //     System.err.println("Exception:"+ex+" while trying to sleep WatchDir thread");
          //     ex.printStackTrace();
          // }
        }
      }

      // reset key and remove from set if directory no longer accessible
      boolean valid = key.reset();
      if (!valid) {
        keys.remove(key);

        // all directories are inaccessible
        if (keys.isEmpty()) {
          break;
        }
      }
    }
  }