I have this method in my Controller that from indexAction() is called several times. Should I keep it as it is, or should I create Helper Class (Service) for it and other reusable methods, since I could avoid passing arguments such as `$em` in this case? I can't understand a context of services and when it is comfortable to use them. 

```
public function getProfile($em, $username, $password) {
    $dql = $em->createQuery('SELECT Profiles FROM ProjectProjectBundle:Profiles AS Profiles WHERE Profiles.email = :email AND Profiles.password = :password')
        ->setParameters(array(
                'email' => $username,
                'password' => $password
            ));
    return $dql->getArrayResult();
}

```