private boolean isValidChild(@NotNull VirtualFile file, @NotNull Project project) {
      if (file.is(SYMLINK) && VfsUtilCore.isInvalidLink(file)) return false; // ignore invalid symlink
      AreaInstance area = ProjectFileNode.findArea(file, project);
      return area != null && (id instanceof VirtualFile || id.equals(area));
    }
private boolean isValidChild(@NotNull VirtualFile file, @NotNull Project project)