private void fileCreated(@NotNull VFileCreateEvent event) {
        VirtualFile f = event.getFile();
        DocumentReference ref = f == null ? null : myDeletedFilePathToRef.remove(new FilePath(f.getUrl()));
        if (ref != null) {
          f.putUserData(FILE_TO_REF_KEY, new WeakReference<>(ref));
          ((DocumentReferenceByVirtualFile)ref).update(f);
        }
      }
private void fileCreated(@NotNull VFileCreateEvent event)