Service to manage ad group asset set

[Proto definition ![GitHub](https://developers.google.com/site-assets/logo-github.svg)](https://github.com/googleapis/googleapis/blob/master/google/ads/googleads/v25/services/ad_group_asset_set_service.proto)
The following methods are available for this service:

- [MutateAdGroupAssetSets](https://developers.google.com/google-ads/api/reference/rpc/v25/AdGroupAssetSetService/MutateAdGroupAssetSets)