public function define_course_plugin_structure() {
        global $DB;

        // Since this method is executed before the restore we can do some pre-checks here.
        // In case of merging backup into existing course find the current number of sections.
        $target = $this->step->get_task()->get_target();
        if (($target == backup::TARGET_CURRENT_ADDING || $target == backup::TARGET_EXISTING_ADDING) &&
                $this->is_pre_33_backup()) {
            $maxsection = $DB->get_field_sql(
                'SELECT max(section) FROM {course_sections} WHERE course = ?',
                [$this->step->get_task()->get_courseid()]);
            $this->originalnumsections = (int)$maxsection;
        }

        // Dummy path element is needed in order for after_restore_course() to be called.
        return [new restore_path_element('dummy_course', $this->get_pathfor('/dummycourse'))];
    }