private static function createDefaultPartition(
        AdWordsServices $adWordsServices,
        AdWordsSession $session,
        $adGroupId
    ) {
        $adGroupCriterionService =
            $adWordsServices->get($session, AdGroupCriterionService::class);

        // Creates an ad group criterion for 'All products'.
        $productPartition = new ProductPartition();
        $productPartition->setPartitionType(ProductPartitionType::UNIT);

        // Creates a biddable ad group criterion.
        $criterion = new BiddableAdGroupCriterion();
        $criterion->setAdGroupId($adGroupId);
        $criterion->setCriterion($productPartition);

        // Creates an ad group criterion operation.
        $operation = new AdGroupCriterionOperation();
        $operation->setOperand($criterion);
        $operation->setOperator(Operator::ADD);

        $addedAdGroupCriterion = $adGroupCriterionService->mutate([$operation])
            ->getValue()[0];
        printf(
            "Ad group criterion with ID %d in ad group with ID %d"
            . " was added.%s",
            $addedAdGroupCriterion->getCriterion()->getId(),
            $addedAdGroupCriterion->getAdGroupId(),
            PHP_EOL
        );
    }