private static boolean isJdkElement(PsiElement element, final @NotNull Project project) {
    final VirtualFile file = PsiUtilCore.getVirtualFile(element);
    if (file != null) {
      List<OrderEntry> orderEntries = ProjectRootManager.getInstance(project).getFileIndex().getOrderEntriesForFile(file);
      if (!orderEntries.isEmpty() && orderEntries.get(0) instanceof JdkOrderEntry) {
        return true;
      }
    }
    return false;
  }
private static boolean isJdkElement(PsiElement element, final @NotNull Project project)