public function testGetFilter($groups = null, $expect = null)
{
/* setup */
Db::forTablePrefix('users')->whereIdIs(1)->findOne()->set('groups', $groups)->save();
$auth = new Auth($this->_request);
$auth->login(1);
/* actual */
$actual = $auth->getFilter();
/* compare */
$this->assertEquals($expect, $actual);
}