public static function create_calendar_events($events) {
        global $DB, $USER;

        // Parameter validation.
        $params = self::validate_parameters(self::create_calendar_events_parameters(), array('events' => $events));

        $transaction = $DB->start_delegated_transaction();
        $return = array();
        $warnings = array();

        foreach ($params['events'] as $event) {

            // Let us set some defaults.
            $event['userid'] = $USER->id;
            $event['modulename'] = '';
            $event['instance'] = 0;
            $event['subscriptionid'] = null;
            $event['uuid']= '';
            $event['format'] = external_validate_format($event['format']);
            if ($event['repeats'] > 0) {
                $event['repeat'] = 1;
            } else {
                $event['repeat'] = 0;
            }

            $eventobj = new calendar_event($event);

            // Let's check if the user is allowed to delete an event.
            if (!calendar_add_event_allowed($eventobj)) {
                $warnings [] = array('item' => $event['name'], 'warningcode' => 'nopermissions', 'message' => 'you do not have permissions to create this event');
                continue;
            }
            // Let's create the event.
            $var = $eventobj->create($event);
            $var = (array)$var->properties();
            if ($event['repeat']) {
                $children = $DB->get_records('event', array('repeatid' => $var['id']));
                foreach ($children as $child) {
                    $return[] = (array) $child;
                }
            } else {
                $return[] = $var;
            }
        }

        // Everything done smoothly, let's commit.
        $transaction->allow_commit();
        return array('events' => $return, 'warnings' => $warnings);
    }