public function testIsPropertySet()
{
$user = new User();
$value = isset($user->notDefined);
self::assertEquals(false, $value);
$value = isset($user->login);
self::assertEquals(true, $value);
$userGroup = new UserGroup();
$value = isset($userGroup->notDefined);
self::assertEquals(false, $value);
$value = isset($userGroup->parentId);
self::assertEquals(true, $value);
}