void removeNode(@NotNull FilePointerPartNode node, VirtualFilePointerListener listener) {
   boolean rootNodeEmpty = node.remove();
   if (rootNodeEmpty) {
     myPointers.remove(listener);
   } else {
     myPointers.get(listener).checkConsistency();
   }
 }
  @Override
  public void after(@NotNull final List<? extends VFileEvent> events) {
    incModificationCount();

    for (FilePointerPartNode node : myPointersToUpdateUrl) {
      synchronized (this) {
        VirtualFilePointerImpl pointer = node.leaf;
        String urlBefore = pointer.getUrlNoUpdate();
        Pair<VirtualFile, String> after = node.update();
        String urlAfter = after.second;
        if (URL_COMPARATOR.compare(urlBefore, urlAfter) != 0) {
          // url has changed, reinsert
          FilePointerPartNode root = myPointers.get(pointer.getListener());
          int useCount = node.useCount;
          node.remove();
          FilePointerPartNode newNode =
              root.findPointerOrCreate(VfsUtilCore.urlToPath(urlAfter), 0, after);
          VirtualFilePointerImpl existingPointer = newNode.leaf;
          if (existingPointer != null) {
            // can happen when e.g. file renamed to the existing file
            // merge two pointers
            pointer.myNode = newNode;
          } else {
            newNode.associate(pointer, after);
          }
          newNode.incrementUsageCount(useCount);
        }
      }
    }

    VirtualFilePointer[] pointersToFireArray = toPointers(myPointersToFire);
    for (VirtualFilePointer pointer : pointersToFireArray) {
      ((VirtualFilePointerImpl) pointer).myNode.update();
    }

    for (EventDescriptor event : myEvents) {
      event.fireAfter();
    }

    if (pointersToFireArray.length != 0) {
      myBus.syncPublisher(VirtualFilePointerListener.TOPIC).validityChanged(pointersToFireArray);
    }

    myPointersToUpdateUrl = Collections.emptyList();
    myEvents = Collections.emptyList();
    myPointersToFire = Collections.emptyList();
    for (FilePointerPartNode root : myPointers.values()) {
      root.checkConsistency();
    }
  }