@Nullable
  public ExcludeFolder addExcludeFolder(@NotNull final VirtualFile file) {
    try {
      return doAddExcludeFolder(file);
    }
    finally {
      myEventDispatcher.getMulticaster().folderExcluded(this, file);
      update();
    }
  }
@Nullable
  public ExcludeFolder addExcludeFolder(@NotNull final VirtualFile file)