public function get_samples($sampleids) {
        global $DB;

        list($sql, $params) = $DB->get_in_or_equal($sampleids, SQL_PARAMS_NAMED);
        $courses = $DB->get_records_select('course', "id $sql", $params);

        $courseids = array_keys($courses);
        $sampleids = array_combine($courseids, $courseids);

        $courses = array_map(function($course) {
            return array('course' => $course, 'context' => \context_course::instance($course->id));
        }, $courses);

        // No related data attached.
        return array($sampleids, $courses);
    }