MyAuthorizationService.php

<?php

namespace MyModule\Service;

use ZfcRbac\Service\AuthorizationService as BaseAuthorizationService;

class AuthorizationService extends BaseAuthorizationService
{
    protected $myDependency;

    public function __construct(Rbac $rbac, RoleService $roleService, AssertionPluginManager $assertionPluginManager, $myDependency = null)
    {
        parent::__construct($rbac, $roleService, $assertionPluginManager);

        $this->myDependency = $myDependency;
    }
}