public function getInstance($sInstanceName)
    {
        if (strpos($sInstanceName, '\\') === false) {
            $sInstanceName = $this->getClass($sInstanceName);
        }
        if (!isset(Core::$_aInstances[$sInstanceName])) {
            Core::$_aInstances[$sInstanceName] = new $sInstanceName();
        }

        return Core::$_aInstances[$sInstanceName];
    }