ServiceManager into Service models

Module.php

public function getServiceConfig()
{
	return array(
		'factories' => array(
      'Application\Service\PlayerService' => function ($sm) {
      	$model = new Service\PlayerService($sm);
      	return $model;
      }
    )
  );
}

PlayerService.php

<?php

namespace Application\Service;

class PlayerService
{
  private $sm;

	public function __construct ($sm)
	{
		$this->sm = $sm;
	}

	public function register(Entity\User $user)
	{
		$identity = $this->sm->get('Zend\Authentication\AuthenticationService');
	}
}