public static @NotNull @Unmodifiable List<String> findAllEnclosingLabels(@NotNull PsiElement start) {
    List<String> result = new SmartList<>();
    for (PsiElement context = start; !isCodeBoundary(context); context = context.getContext()) {
      if (context instanceof PsiLabeledStatement) {
        result.add(((PsiLabeledStatement)context).getName());
      }
    }
    return result;
  }
public static @NotNull @Unmodifiable List<String> findAllEnclosingLabels(@NotNull PsiElement start)