public static function clearGroup($group, $config = 'default') {
		if (!self::isInitialized($config)) {
			return false;
		}
		$start = microtime(true);
		$success = self::$_engines[$config]->clearGroup($group);
		self::__logActivity($config, 'clearGroup', '', $success, $start);
		self::set(null, $config);

		self::$_queriesCount['total']++;

		return $success;
	}