public static function get_course_image($course) {
        global $CFG;
        $courseinlist = new \core_course_list_element($course);
        foreach ($courseinlist->get_course_overviewfiles() as $file) {
            if ($file->is_valid_image()) {
                $pathcomponents = [
                    '/pluginfile.php',
                    $file->get_contextid(),
                    $file->get_component(),
                    $file->get_filearea() . $file->get_filepath() . $file->get_filename()
                ];
                $path = implode('/', $pathcomponents);
                return (new moodle_url($path))->out();
            }
        }
        return false;
    }