protected function showOptionalAdditionalInfo()
    {
        $this->command->info('See step by step tutorial at:');
        $url = 'https://blog.damirmiladinov.com/laravel/laravel-5.2-socialite-google-login.html';
        $this->command->info(' <question>' . $url . '</question>');
        $this->command->info('Remember to enable Google+ API!');
        $this->command->info('More info at:');
        $url = 'https://developers.google.com/identity/sign-in/web/devconsole-project';
        $this->command->info(' <question>' . $url . '</question>');
    }