Laravel transaction return null

I am trying to query with db transaction .When my method run that time data inserted correctly in corresponding table.but it return null.

My Code

    return $result = DB::transaction(function() use ($attributes) {
        $service = $this->service->create($attributes);
        $visibilityAttributes = $attributes['dropdown_option_id'];
        $visibilityAttributes = array_map('intval', $visibilityAttributes);
        $service->visibility()->sync($visibilityAttributes);
    },3);

via Chebli Mohamed