Controller.php

<?php
/**
 * Piwik - free/libre analytics platform
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 */

namespace Piwik\Plugins\TestRunner;

class Controller extends \Piwik\Plugin\Controller
{
    public function check()
    {
        return 'OK';
    }
}