plugins/ExampleAPI/ExampleAPI.php

<?php

/**
 * Matomo - free/libre analytics platform
 *
 * @link    https://matomo.org
 * @license https://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 */

namespace Piwik\Plugins\ExampleAPI;

/**
 * This plugin only provides an API.php file, so we leave the plugin class empty
 *
 */
class ExampleAPI extends \Piwik\Plugin
{
}