public function postDeletePostalAddress(Request $request)
    {
        $pa = PostalAddress::findOrFail($request->input('postal_address_id'));

        if ($pa->user->userId != Auth::user()->userId) {
            return redirect('/account/postal-addresses')
                ->withErrors(["You can only delete your own postal addresses."]);
        }

        if ($pa->purchases()->count()) {
            return redirect('/account/postal-addresses')
                ->withErrors(["You cannot delete postal addresses that are associated with purchases."]);
        }

        $pa->delete();

        return redirect('/account/postal-addresses')
            ->withStatus('Postal address deleted.');
    }