The type of the experiment asset detail operation.

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v25/enums/experiment_asset_detail_operation.proto)

| Enums ||
|---|---|
| ## `ADD` | Asset is attached to the ad. |
| ## `REMOVE` | Asset is removed from the ad. |
| ## `UNKNOWN` | The value is unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |