public function getRole()
    {
        if ( null === $this->role )
        {
            $auth = $this->getAuthenticationService();

            if ( $auth->hasIdentity() )
            {
                $this->role = $auth->getIdentity();
            }
            else
            {
                $this->role = new Acl\Role\GenericRole( self::ROLE_GUEST_ID );
            }
        }

        return $this->role;
    }