public static function findAllInstances()
    {
        $ret = array();
        $modelProviders = Kwf_Config::getValueArray('modelProviders');
        foreach ($modelProviders as $modelProvider) {
            if ($modelProvider) {
                $modelProvider = new $modelProvider;
                $ret = array_merge($modelProvider->findModels(), $ret);
            }
        }
        $ret = array_unique($ret, SORT_REGULAR);
        return $ret;
    }