public function scopeBySurveyType(Builder $query, ?SurveyType $survey_type = null): Builder 	{ 		return $query->whereHas('survey', function ($query) use ($survey_type) { 			$query->when($survey_type, function ($query) use ($survey_type) { 				$query->where('type', $survey_type->value); 			}); 		}); 	}