private function deAuthorize(User $user): void
    {
        $client = new Client;

        $client->delete("https://graph.facebook.com/{$user->id}/permissions",
            [
                'headers' => ['Accept' => 'application/json'],
                'form_params' => [
                    'access_token' => $user->token,
                ],
            ]
        );
    }