private static function deleteCampaignFeed(
        AdWordsServices $adWordsServices,
        AdWordsSession $session,
        $campaignFeed
    ) {
        $campaignFeedService = $adWordsServices->get($session, CampaignFeedService::class);

        printf(
            "Deleting association of feed ID %d and campaign ID %d...\n",
            $campaignFeed->getFeedId(),
            $campaignFeed->getCampaignId()
        );

        $operation = new CampaignFeedOperation();
        $operation->setOperand($campaignFeed);
        $operation->setOperator(Operator::REMOVE);

        return $campaignFeedService->mutate([$operation]);
    }