ORM::reset_db PHP Method

    public static function reset_db()
    {
        self::$_db = array();
    }

/**
 * Adding Middle Layer to authenticate every request
 * Checking if the request has valid api key in the 'Api-Key' header
 */
function mw_auth()
{
    // Master DB
    include_once SessionData::getInstance()->getRootDir() . '/config/database.php';
    ORM::configure('mysql:host=' . DB_HOST . ';dbname=' . DB_NAME . '');
    ORM::configure('username', DB_USERNAME);
    ORM::configure('password', DB_PASSWORD);
    ORM::configure('logging', true);
    ORM::configure('driver_options', array(PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES utf8'));
    ORM::reset_db();
    // Datum setzen
    date_default_timezone_set('Europe/Berlin');
    // Getting request headers
    $headers = apache_request_headers();
    $response = array();
    $app = \Slim\Slim::getInstance();
    // Verifying Authorization Header
    if (isset($headers['Api-Key'])) {
        $apikey = $headers['Api-Key'];
        // API-KEY vorhanden?
        $user = ORM::for_table('user')->where('api_key', $apikey)->find_one();
        if ($user != null) {
            // API aktiviert?
            if ($user['active'] == 1) {
                // Everything is OK
                // Set Session Data
                SessionData::getInstance()->setUserId($user['id']);
            } else {
                $response["error"] = true;
                $response["message"] = "API-Key not activated!";
                echoResponse(400, $response);
                $app->stop();
            }
        } else {
            $response["error"] = true;
            $response["message"] = "API-KEY unknown!";
            echoResponse(400, $response);
            $app->stop();
        }
    } else {
        // api key is missing in header
        $response["error"] = true;
        $response["message"] = "Api key is missing";
        echoResponse(400, $response);
        $app->stop();
    }
}