/**
  * Register the service provider.
  *
  * @return void
  */
 public function register()
 {
     //
     //
     Question::created(function ($question) {
         UserLog::create(['operation' => 'create', 'user_id' => user() ? user()->id : NULL, 'reference_key' => 'question', 'reference_id' => $question->id]);
     });
     Question::updated(function ($question) {
         UserLog::create(['operation' => 'update', 'user_id' => user() ? user()->id : NULL, 'reference_key' => 'question', 'reference_id' => $question->id]);
     });
     Question::deleted(function ($question) {
         UserLog::create(['operation' => 'delete', 'user_id' => user() ? user()->id : NULL, 'reference_key' => 'question', 'reference_id' => $question->id]);
     });
 }