Order::getFirstRequisiteId

private function getFirstRequisiteId(int $contactId): ?int
{
	$requisite = EntityRequisite::getSingleInstance()->getList(
		[
			'select' => ['ID'],
			'order' => [
				'SORT' => 'ASC',
				'ID' => 'ASC'
			],
			'filter' => [
				'=ENTITY_TYPE_ID' => CCrmOwnerType::Contact,
				'=ENTITY_ID' => $contactId
			],
			'limit' => 1,
		]
	)->fetch();

	if (!$requisite)
	{
		return null;
	}

	return (int)$requisite['ID'];
}