@NotNull
  public static Collection<PsiField> collectClassFieldsIntern(@NotNull PsiClass psiClass) {
    if (psiClass instanceof PsiExtensibleClass) {
      return ((PsiExtensibleClass) psiClass).getOwnFields();
    } else {
      return filterPsiElements(psiClass, PsiField.class);
    }
  }
@NotNull
  public static Collection<PsiField> collectClassFieldsIntern(@NotNull PsiClass psiClass)