A single operation (create, remove) on a campaign asset set.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v26/services/campaign_asset_set_service.proto)

| Fields ||
|---|---|
| ## `operation` Union field. The mutate operation. `operation` can be only one of the following: ||
| ### `create` | `https://developers.google.com/google-ads/api/reference/rpc/v26/CampaignAssetSet` Create operation: No resource name is expected for the new campaign asset set. |
| ### `remove` | `string` Remove operation: A resource name for the removed campaign asset set is expected, in this format: `customers/{customer_id}/campaignAssetSets/{campaign_id}~{asset_set_id}` |