public function execute() {
        global $CFG;

        require_once($CFG->dirroot . '/mod/assign/locallib.php');
        \assign::cron();

        $plugins = \core_component::get_plugin_list('assignsubmission');

        foreach ($plugins as $name => $plugin) {
            $disabled = get_config('assignsubmission_' . $name, 'disabled');
            if (!$disabled) {
                $class = 'assign_submission_' . $name;
                require_once($CFG->dirroot . '/mod/assign/submission/' . $name . '/locallib.php');
                $class::cron();
            }
        }
        $plugins = \core_component::get_plugin_list('assignfeedback');

        foreach ($plugins as $name => $plugin) {
            $disabled = get_config('assignfeedback_' . $name, 'disabled');
            if (!$disabled) {
                $class = 'assign_feedback_' . $name;
                require_once($CFG->dirroot . '/mod/assign/feedback/' . $name . '/locallib.php');
                $class::cron();
            }
        }

        return true;
    }