protected function createSQLite($pool)
    {
        $hasApcu = function_exists('apcu_fetch');
        // TODO: Maybe implement StateL1SQLite class instead of NULL one.
        $state = $hasApcu ? new StateL1APCu("sqlite-$pool") : new StateL1Static();
        $cache = new SQLiteL1($pool, $state);
        return $cache;
    }