필드 마스크

    $campaign = new Campaign([
        'resource_name' => ResourceNames::forCampaign($customerId, $campaignId),
        'status' => CampaignStatus::PAUSED
    ]);

    $campaignOperation = new CampaignOperation();
    $campaignOperation->setUpdate($campaign);
    $campaignOperation->setUpdateMask(FieldMasks::allSetFieldsOf($campaign));

// Creates a campaign with the proper resource name and an empty
// MaximizeConversions field.
$campaign = new Campaign([
    'resource_name' => ResourceNames::forCampaign($customerId, $campaignId),
    'maximize_conversions' => new MaximizeConversions()
]);

// Constructs an operation, using the FieldMasks' allSetFieldsOf utility to
// derive the update mask. The field mask will include 'maximize_conversions`,
// which will produce a FieldMaskError.FIELD_HAS_SUBFIELDS error.
$campaignOperation = new CampaignOperation();
$campaignOperation->setUpdate($campaign);
$campaignOperation->setUpdateMask(FieldMasks::allSetFieldsOf($campaign));

// Sends the operation in a mutate request that will result in a
// FieldMaskError.FIELD_HAS_SUBFIELDS error because empty MESSAGE fields cannot
// be included in a field mask.
$campaignServiceClient = $googleAdsClient->getCampaignServiceClient();
$response = $campaignServiceClient->mutateCampaigns($customerId, [$campaignOperation]);

// Creates a Campaign object with the proper resource name.
$campaign = new Campaign([
    'resource_name' => ResourceNames::forCampaign($customerId, $campaignId)
]);

// Creates a field mask from the existing campaign and adds all of the mutable
// fields (only one in this case) on the MaximizeConversions bidding strategy to
// the field mask. Because this field is included in the field mask but
// excluded from the campaign object, the Google Ads API will set the campaign's
// bidding strategy to a MaximizeConversions object without any of its subfields
// set.
fieldMask = FieldMasks::allSetFieldsOf($campaign);
// Only include 'maximize_conversions.target_cpa_micros' in the field mask
// as it is the only mutable subfield on MaximizeConversions when used as a
// standard bidding strategy.
//
// Learn more about standard and portfolio bidding strategies here:
// https://developers.google.com/google-ads/api/docs/campaigns/bidding/assign-strategies
$fieldMask->setPaths(array_merge(
    iterator_to_array($fieldMask->getPaths()->getIterator()),
    ['maximize_conversions.target_cpa_micros']
));

// Creates an operation to update the campaign with the specified fields.
$campaignOperation = new CampaignOperation();
$campaignOperation->setUpdate($campaign);
$campaignOperation->setUpdateMask($fieldMask);

// Creates a campaign with the proper resource name and a MaximizeConversions
// object with target_cpa_micros set to 0.
$campaign = new Campaign([
    'resource_name' => ResourceNames::forCampaign($customerId, $campaignId),
    'maximize_conversions' => new MaximizeConversions(['target_cpa' => 0]),
    'status' => CampaignStatus::PAUSED
]);

// Constructs an operation, using the FieldMasks' allSetFieldsOf utility to
// derive the update mask. However, the field mask will NOT include
// 'maximize_conversions.target_cpa_micros'.
$campaignOperation = new CampaignOperation();
$campaignOperation->setUpdate($campaign);
$campaignOperation->setUpdateMask(FieldMasks::allSetFieldsOf($campaign));

// Sends the operation in a mutate request that will succeed but will NOT update
// the 'target_cpa_micros' field because
// 'maximize_conversions.target_cpa_micros' was not included in the field mask.
$campaignServiceClient = $googleAdsClient->getCampaignServiceClient();
$response = $campaignServiceClient->mutateCampaigns($customerId, [$campaignOperation]);

// Creates a Campaign object with the proper resource name.
$campaign = new Campaign([
    'resource_name' => ResourceNames::forCampaign($customerId, $campaignId)
]);

// Constructs a field mask from the existing campaign and adds the
// 'maximize_conversions.target_cpa_micros' field to the field mask, which will
// clear this field from the bidding strategy without impacting any other fields
// on the bidding strategy.
$fieldMask = FieldMasks::allSetFieldsOf($campaign);
$fieldMask->setPaths(array_merge(
    iterator_to_array($fieldMask->getPaths()->getIterator()),
    ['maximize_conversions.target_cpa_micros']
));

// Creates an operation to update the campaign with the specified field.
$campaignOperation = new CampaignOperation();
$campaignOperation->setUpdate($campaign);
$campaignOperation->setUpdateMask($fieldMask);