Enum describing possible source of asset.

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

| Enums ||
|---|---|
| ## `ADVERTISER` | The asset or asset link is provided by advertiser. |
| ## `AUTOMATICALLY_CREATED` | The asset or asset link is generated by Google. |
| ## `UNKNOWN` | Used for return value only. Represents value unknown in this version. |
| ## `UNSPECIFIED` | Not specified. |