public function queryKeysWithoutStatsKey(UnitTester $I)
{
$I->wantTo('Catch exception during the attempt getting cache keys by using Redis as cache backend without statsKey');
$cache = new Redis(new Data(['lifetime' => 20]), ['host' => TEST_RS_HOST, 'port' => TEST_RS_PORT]);
$I->expectException(new Exception("Cached keys need to be enabled to use this function (options['statsKey'] == '_PHCM')!"), function () use($cache) {
$cache->queryKeys();
});
}