NullStrategy.php

См. документацию.

<?php
 
namespace Bitrix\Calendar\Relation\Strategy;
 
use Bitrix\Calendar\Relation\Item\Relation;
use Bitrix\Calendar\Relation\Exception\RelationException;
 
class NullStrategy extends RelationStrategy
{

    public function getRelation(): Relation
    {
        throw new RelationException('Unknown type of event relation');
    }
}