Get model in parent controller

How can I pass, or otherwise "infer" the model of a child controller from within a parent controller using Laravel 5.1? I need this functionality as I'm adding a generic method in my parent controller which all children can use.

I've tried passing and inferring with 500 errors.

Child Controller:

use App\UserQuestion;

class UserQuestions extends ResourceController
{
    $this->parentMethod($input, UserQuestion);
}

Parent Controller:

class ResourceController extends Controller
{
    protected function parentMethod($input, Model $model) 
    {
         $childTableName = $model->getTable();
    }

via Chebli Mohamed