@Override
  public void fillFiles(Set<? super PsiFile> set, boolean recursively) {
    super.fillFiles(set, recursively);
    final PsiFile file = getFile();
    if (file != null && file.isValid()) {
      set.add(file);
    }
  }
@Override
  public void fillFiles(Set<? super PsiFile> set, boolean recursively)